Honda CB750 Sandcast
General Category => General Discussion => Topic started by: Wayne on March 02, 2010, 07:36:02 pm
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My old friend is offering me his 69. I used to ride this bike in the later 70's. It has not been ridden since but I'm told the engine has been run as recently as summer 2009. I'm not sure what to offer him if it is a sancast model. As far as I know the only thing not original on the bike is the handlebars. It wil need a major resoration due to corrosion etc.
What should I look for on this bike to come to some kind of buying price?
I know to look for engine number between CB750 1000001 to CB750 1007414. I'l look for a "wrinkle" tank, cast gas cap? I'm told the exhaust is good and a candidate for re-chroming. Is there anything I should look for on the exhaust? Numbers etc?
Any help on putting a value on this piece (assuming it's a sandcast) would be appreciated. Other rare parts/features I should look for? I think I can pick it up for $2500.00 - $3000.00 Canadian. Thanks!
Oh, the bike has about 30,000 miles on it. Only a few more than when I used to ride it in the late 70's!
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Hi Bzzrd2
Sounds like you associate good memories with the bike, so the bike should be worth to you whatever the price you decide to pay.
If you would be so kind as to include your first name with your posts, that would be appreciated.
The reason we ask this, is so all of us who frequent this board can avoid the depersonalization of the cyber-age. We want to get to know each other on a first name basis, if nothing else than for the sake of virtual time commraderie.
For questions you have about sandcast features distinguishing from non-sandcast, you will be rewarded by doing a search of this BB as well as study the website. Many of your questions will be answered in just the past couple posts on this BB.
As a result of sharing on the BB the finds of your diligent study of your new bike and what you learn in comparison to what is in the website, we all learn and will virtually have a good time together in the real time of our individually looking at our monitor screens.
9-hole clutch cover is the hallmark identifier of sandcast crank cases.
Any non-sandcast "K0" that is complete and correct unless it is horrifically rusted, rotted or seized should be worth $2-3k.
Good Luck in your pursuit - keep us updated !
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Thanks Steve
I hope to get down and look at the bike soon. It's been a long time since I last laid eyes on it. Yes, I do have fond memories of riding it when I was younger. It was more reliable than the Brit bikes I was riding at the time so my friend was always willing to let me use it! I'll post my findings once I get down to view it.
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Wayne, Good luck !
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Well, I got down to look at the bike. Unfortunately I was not well prepared and the owner was not home so all I could do was get into his crammed little shed and gather what info I could. The bike has not been stored well, but it is not rotten. The tank is clean inside with no signs of rust. I couldn't check to see if it was siezed as the owner had it tight to the wall. The carb slides moved so I'm hoping the pistons will too. The wheels have light rust speckles and are candidates for re-chrome I believe. Same with the fenders. The mufflers have been changed to an aftermarket brand. (I remember now that the owner changed them out on a trip to Florida and left his originals behind) The front end has a dual disk setup which I'm assuming must be aftermarket as well. The gas cap itself felt loose but did latch. Couldn't get the frame number but I do know for sure that the engine and frame are a match as I know this bike's history. That's really all I could gather withough help and some light. I'm going back on Jan 17 2010. Hopefully I can be better prepared and better educated on the rarer items I should look for.
Lastly, I did get the engine number and I do know that nothing has ever been replaced on this engine other than the maintainance items.
CB 750E - 1000748
Oh yes. as I mentioned the handlebars are not Honda.
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Hi Wayne,
Your #748 engine vin is what would be considered an early production.
It's pretty much worth whatever you pay for it.
If it is all there other than exhaust, you are lucky. Correct early prod parts are nearly impossible to find.
If you are lucky enough to get the bike, THROW NOTHING AWAY.
Many of the parts on that early of a vin are unique to the vin.
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Thanks Steve. Like I said, as far as I know just the handelbars and mufflers were replaced. The header pipes don't even have any rust on them. He painted it some crap brown with flames but the tins and side covers etc. are in good shape from what I can see. I did forget to say, the air intake box is cracked. What about that dual disk setup on the front? Is it from an aftermarket or did Honda offer it on these bikes? I looked at a lot of sancast pictures and I don't see any with dual disk.
I'll make him an offer when I go down on Sunday. I hate to see something like this sitting, not properly stored. I'm not sure if I will restore it or sell it. I do custom builds, mainly Harley and Brit bikes. I don't know if I have the patience to do a restoration like this justice. I'll have to ponder it.
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Wayne:
Sounds like you have found an early production sandcast. If/when you get the sandcast what ever you decide to do sell or restore it is nice to know another piece of Honda history has been found. Marty K.
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I have gone through the site and picked out what I believe are the the crtical things to look for. The way I see it, even if the bike is only 90% original, it's a nice start for someone. If I don't take on the restoration you can be assured it will be offered up to people who will respect this old girl for what she is.
Thanks for your help so far folks. I'll post more details on the bike on Jan 17th or 18th.
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Handle bars can be purchsed from Honda.
So can exhaust, unless one wants to go to the more authentic Yamiya's.
The air box is most likely the early "2-hole" type, but would be interesting to know if upper half is the earlier no relief type or the later type w/ relief.
The brake hoses and oil lines are unique.
It may have the pointerless kill knob, the the brake fluid reservoir has no leveling line, as well as the short neck petcock and the narrow tongue upper triple clamp.
The list goes on......
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Got down to see the bike again and drug it out into some daylight. I'm a bit less optimistic about this old girl. She does need a lot of work. I couldn't see the air intake box as it was in the owners basement along with one side cover and a spare seat he has. He's a trucker and hard to catch at home. I wrote the frame number down but lost the paper! Just a bad day...from the pics it looks like:
Frame - 1000578
Engine - 1000742
It does have a few good pieces as you will see in the pics but also some bad ones such as the instrumentation. I was most disapointed to see a bent fin on the cylinders and a bent/cracked one on the head. No pieces missing but I have no idea if this is smething that can be repaired to look "correct". It is obvious it was caused through neglect in the tight shed and it's probably how the air intke box got cracked. The inside of the fuel tank is almost like new. The owner did say he put gas in it and ran it in August then drained the fuel. I now believe him as you will see where he put a bolt in the fuel line to seal it off rather than reconnecting it. As well, the engine kicks over beautifully which was nice to see. Compression feels good as I went slowly through all cylinders. I remembered the bike having around 30K miles. The odometer is reading 29K and change. I was probably the last to ride the bike somewhere around 1979 or 80! I wish I had of brought it home with me then. Hindsight is 20/20!
Any comments that would help on whether or not this is a viable purchase/project would be appreciated.
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More pics...
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Hi Wayne,
Be ye not discouraged nor faint of heart !
There is NOTHING that cannot be restored or brought back to original. All it takes is patience, time and money.
If you can handle a set of wrenches, we have the expertise to walk you through whatever the path you take.
This 41 year old bike is a low "matching" set of vins.
There is no such thing as bad pieces on an early sandcast.
Everything about this bike is good.
From a collector's standpoint, the 578/E742 combination is quite desirable. Well worth every penny of what you said the asking price to be.
In an attempt to squelch your doubt, anwering your question, "The bike is a very viable project, if you don't buy it, you'll miss a great purchase!"
If it were me, i would be "robbing the bank," or "selling a kid," so to speak !
The bent fins are no problem. Using MAP gas with a propane torch head, thoroughly heat up one fin at a time, using a pair of wide flat jawed electrical type pliers, you can move that fin back to it's original position. Once the aluminum is brought to a working temp, using a set of previously mentioned pliers, get a good grip, slowly exert pressure and you will feel the metal (fin) move slowly into place. The cracked fin should be able to be moved back to original position so as to not notice any glaring defect. A good welder can replace broken fins.
Neither my 232 or 4363 were as good condition as this bike. There are many approaches you can take to getting it back on the road, anywhere from making it all correct and road worthy to a full restoration. You can always make it road worthy, enjoy it in it's unrestored condition, buy and save up parts for a restoration at a later date.
Appears to have wrong kill switch (red knob.) Funky horn.
Has a 17 litre tank. Smooth ferrule oil lines. Ringless brake reservoir. Short ring nuts on gauge cable. RH mirror stem appears rare 11mm.
Dual disc brake is original parts, really a desirable setup.
I would not hesitate for a moment to buy the bike. Tell the owner what it will take to make the bike road worthy, what it is missing to make it complete and strike a deal !!!!
If you decide against it, post the owner's contact information so a club member can buy it.
Or, buy it to sell and realise a nice profit.
The bike deserves to be kept whole and saved before it rots into oblivion.
For God's sakes man, buy it, before someone robs it out of your back yard !!!!
If you truly decide the project is not for you, at least have a hand in making sure the bike gets a good home with a clubmember.
This bike deserves more than what it is getting now.
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Thank you Steve
I do consider myself a pretty good wrench. I have been desricbed by others a a "wizard" when it comes to anything technical but if there was ever a humble guy, I'm it. I guess I just needed to hear what you had to say. The bent fin and crack had me most worried. I do have a friend who has a machine shop with expert metal tech's and welders. The did a nice job modifying a case and reinforcing critical areas on a custom Triumph I'm building. (old pot metal cases)
I think what I'll do at this point is buy the bike, get it running and put it in proper storage here. Once I have my current project completed I'll take inventory of the bike and go from there.
For storage I usually add fresh oil throughout and filters.
Fill with fuel and add Fuel Stabiliazer (should I allow the carbs to fill with stabilized fuel on these or leave them empty?)
Lube any good cables etc.
In this case I'll coat good metal areas with WD40.
It won't be going into heated storage but it will be a proper enclosed shelter. Do you think there's anything I should remove from the bike and bring into my basement to save it from further deterioration?
Anything else?
Steve, what about that front brake line. You mentioned the one's that come straight off the Master Cyl are rare. Are there companies that can refurbish those original lines? As you can see, it's a bit rusty and the line itself is weather checked.
I had no idea the dual disc setup would be original. I thought it was a dealer add on or something. Nice if it's original and desireable!
The signal/kill switch threw me as they are gray??? I have only seen black on these things. I'll have to ask the owner what happened to the originlal set. Knowing him, he may have them.
Thanks so much gang,
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Well, as I sit here pouring over Sandcast info the project intruiges me more and more! I have hit up a couple of the Canadian slavage yards to see what they may have hidden away. I'm kind of hoping I may get someone who doesn't know exactly what they are sitting on. Could I be so lucky??? (twice?)
I thought maybe I would start a blog with pictures when I get into the build. Does anyone else here do that? I would love to see some.
I have decided that if I go ahead with this build it will be a "refurbish" rather than a perfect restoration that would have to be trailered around. I want to make it nice, but OK to ride on a nice sunny day.
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Wayne,
Let me not be misunderstood about dual brake caliper setup. Did not come from factory as it is. The 2nd caliper, made up of genuine Honda parts, was added by some proud owner after the bike was sold new. This "upgrade" was not uncommon. I don't know any more about this upgrade, but it was the hot setup, back in the day. I am confident someone in the club knows more of the details on this upgrade.
On the early short neck brake lines, (just like early oil lines) are at this point, rare and irreplaceable. KP was going to look around to see if he could find someone to produce replicas of these early brake lines.
Your plan sounds like a good one, if you're not going to run the bike, but instead put in in long term storage, then what i do, is completely drain tank, let it dry out and then i spray in aersol grease that initally is fluid like, rotate the tank to cover the entire surface area, this aerosol grease then sets up as a film.
Keep us posted. There are many parts on this bike we can examine to determine what parts stopped being used at that particular vin.
Hope you will post more pics of the bike after you get it.
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Thanks Steve
I think I'll go down this weekend and see if I can strike the deal. Once I get it home just list the stuff you want me to take pictures of and I'll do it before I take it to the storage facility. Thanks again.
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Hi Wayne,
Thanks for your reply.
I ask, for a start, just post a good full view of each side and also a good view of each side of engine including oil lines. Also pics of brake line/junction areas, seat pan(s.) As soon as you post them, if there are any more questions, before you take bike to storage, i will ask you.
Glad you made decision to get the bike, you cannot go wrong.
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Steve (or anyone)
Are parts manuals available for these units? Also, What is the best repair manual out there? I would like to start familiarizing myself with all aspects of these machines. I'm a firm believer in the old saying "the body won't go where the mind hasn't already been".
I'm not touching one nut or bolt on this bike until I fully understand not only the mechanical elements, but the rare items that may be unique to this VIN. I understand the latter will be learned from experts such as the people who are members here.
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Hi Wayne,
Your plan sounds like a great one !
Before i start any restoration project, i always obtain the parts and service manuals to study, then i compare what i am reading to the parts making up the actual bike, before, during and after the dis-assembly of the bike.
Did you get the bike yet ?
Yes, Parts Manuals are available, if you want original, your best bet is keep a regular eye open on ebay.
If i recall correctly, the first printing was April 1969, followed by a July printing. These early printings are somewhat rare and expensive. I am not sure what the print date is on the latest CB750 manual. And, quite a few part numbers are correct only for the early vins and not carried over to later vins, in other words, if you look for parts using the pn's from an early manual, these pn's may come back as no longer available, due to being superceded. And, with these early manuals, parts that were used on later vins, are, for obvious reasons not found in the earlier manuals.
After the CB750 manual, comes the K1 manual, the first print date, if i remember correctly, is February 1971. This manual has many of the updated and superceded notations for the CB750, including early vins such as yours. In my opinion, the first printing K1 manual is the best of the lot, it shows in much detail, the changes the CB750 underwent, both from design changes as well as supercession.
Otherwise, if you don't have to have an original parts manual and a copy is ok, someone of us would probably be happy to make you a copy. i have both manuals mentioned above.
As far as Workshop Manual, i like the factory manual the best, they really do a a nice job, as good as any aftermarket manual and it has all the factory pictures in it. I am not sure what the print date ofthe first workshop manula was, i have a 7/69 in rough condition and an 8/69. There was also a thin provisional workshop manual with a print date of June 1969, much different from the typical green covered manual. Either a Clymer or a Chilton's is good as well, i don't care for the Haynes. You can buy an original green cover CB750 manual for a reasonable price, if you don't have to have an early print date, as far as i know, they are all the same. The same CB750 manual was used for the K1 also, there was a K1 (thin) supplement with a brown cover that addressed the service considerations unique to the K1.
Please note, i refer to both these manuals as CB750 manuals, becasue this is what the factory called them. They were not called "K0"manuals, because it was quite some time later before Honda started using the model designation "K0" in any of their literature. If i recall correctly, Honda started using the term "K0" sometime in the early 80's. If anyone knows when the term "K0" was first seen in Honda literature, please post the evidence !
I have not ever seen a K2 onward service manual, but i will assume the manual is referred to by Honda as servicing K2 models.
The factory parts manuals, i have CB750, K1, K2, K3-6 manuals, Honda uses the "K" designation in their manuals all the way from K1-K6, with exception of course, to the 69-70 CB750's from vin 1-44649. "K0" was never a term that was seen in any period factory parts manual, AT LEAST THAT I AM AWARE OF ! The designation of "CB750" was used by Honda in distinguishing machines from vin #1 through 44649. Honda made no distinction bewteen sand and pressure cast bikes in any of their literature, including parts or service manuals, again, AT LEAST THAT I KNOW OF !
But, there is much more to be learned about the CB750, more than we will ever know in our lifetime.
WHEW.......... ! I went off on a tangent there, but i LOVE factory literature as much as i love the actual motorcycle. I collect every piece i can find.
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Thanks Steve
Great info. No, I don't have the bike yet. Spoke to the owner by phone today and he had go away. He's home for part of the day tomorrow (Jan 24) so I may try and get down to see him and see if we can fialize the deal. My brother lives there and is trying to arrange a trailer so I can get it out of there right away. Even though this guy is an old friend of mine he is very bullheaded and gets difficult to deal with when he's drinking (as he was this AM) I want to make sure he doesn't have any leins against the bike so I have to pry the title from his hands and get what's called a "Used Vehicle Package" from the Ministry of Transportations here in Ontario Canada. That will tell me if the bike is free and clear. You never know what this guy might borrow against. I'm not handing hime a dime until we get that document. I'll keep you posted. Thanks again.
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Hi Wayne,
If you need any local assistance....I am just north of the GTA.
........The Other Steve
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Thanks Steve
Nice to know help is close. I'm only about 1.5 hours fromm TO in Trenton. Thanks again.
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Well, we have a deal and I took away some of the parts he had in a box. I'll get the used Vehicle Package today. That will show me the history. It will show one additional owner as my friend put the bike in his brother in laws name when he got divorced. Slippery guy! The attached MTO Safety inspection certificate validates the mileage when that was done. Very few miles were put on the bike since.
The left side cover has a broken mounting tab, a broken screen tab as well as a missing screen.
The air box is a different story. It is more that "cracked" as the owner stated as you can see in the pictures. If these things are better to fix than repplace I am pretty handy working with resins, fiberglass etc. I have assisted in the restoration of a couple of rare 64 split window coupe corvettes where we had to make some hood pieces etc. that could not be purchased. I would look to you guys for advice should I decide to go ahead with this project myself to identify the resin types and the best repair procedure.
The mirror pictured is about 4 1/8" across the face.
So I'll trailer the bike home next weekend, take all the pics the group would like to see, do a compression test etc. and prepare the bike for storage until I make a decision on what to do with it. My friends storage facility is ventilated and has a small ceramic heater. Just enough to keep the dampness down so hopefully we can avoid and further degredation of this unit. Any questions or comments fire away. I'll answer if I can.
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Has the earliest airbox upper case w/ no relief to clear rear frame down tubes.
Measure mirror stems to determine if 10mm or 11mm.
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Steve
It's 10 mm. Has 596563 above a logo that is oval with an M and and S winding through it, and a lower logo near the upper stem looks like an oval with an H in it.
He could only find one mirror when I was there. The one you saw the stem in the pic of the bike was from a Honda Shadow. Good eye thinking it was a 11 mm mirrior though!
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Wayne, Do you see any ink date stamps on the inside of the sidecovers, above or below posts of badge ?
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I only have the one sidecover Steve and no Date stamp. Under high magnification I can see evidence of something just between and a bit below the pegs. It almost looks like a pencil mark but it doesn't wipe off. It is definately a "T" and what appears to be an "O". It's very faint.
The other sidecover is still on the bike so I'm assuming the mounting tabs are all intact. I'll use my Rebel XT for clear high res photos when I get it home.
I do have some curiosity questions though. Why would someone remove the screens from the sidecovers on this bike? Was it something that was done back in the day for a reason?
As well, the damage to the airbox To me it looks like things start to go array by overtorquing and cracking the box. Attempst to repair lead to more problems if not done correctly it would seem. Am I onthe right thought process?
Lastly, just out of curiosity as I haven't decided yet if I'm going to take this project on but, with the damage to the side cover and middle portion of the air box would the guys with experience here fix them, get used replacements or replicas?
I looked at replica mirrors and although they are close they don't appear to have all the markings the one original I have does. I found what appeared to be a Honda replacement part and even it didn't have all the markings. Are the originals desireable in any other way other than 10 mm vs 11 mm?
Sorry for all the questions on a project I haven't even taken on but I am a curious kind of guy.
Lastly, I got the vehicle history today. Unfortunatley it does not show the original owner as it's too old. It only shows my friend and his brother in law as he tranferred it to him when he got divorced so as not to lose it. My friend does think he has the bill of sale from the original owner along with the other mirror. Hopefully he can find them.
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Wayne, you are asking great questions.
I hope you decide to keep the bike, it deserves you.
1. ink dating inside of side covers - Showan calendar dating is used. Hirohito ascended to the throne in 1926, his family name was Showa. 1927 was the first year of the reign of the family Showa. 1969 would be the 43rd year of the reign of the family Showa. The ink calendar dating would be, for example, "43.6.10." Gregorian calendar dating would be "69.6.10" or June 10, 1969. I have no idea when Honda first began ink dating side covers nor do i know when or if all side covers were ink date stamped from the very beginning.
2. no idea why screens were removed. maybe somebody was going to do a paint job? maybe somebody did not like the look of the screens ? i am not aware of screens being removed because of fad behavior. Who knows why these things were done ? If only the bike could talk.........
3. if the side cover looks like a piece from another original side cover could be grafted in, i like Lord Plastic Repair product, Fusor 143. of course one would need to find a donor from another side cover for the part. Lord Plastic Repair product using Fusor 143 and Lord Fusor mesh, with will NOT break in area of repair. No doubt, there are other repair products, but i also know there are problems with other products adhesing to the nasty, rotten, brittle material these parts were made of. My experience, Lord Fusor 143 with mesh, WORKS on this old material.
4. the airbox, i would definitely do anything i could to save the upper half with out the relief for the rear frame down tubes. The middle plate section, in the past i have used the plate from a David Silver Spares pattern box. The lower section, if you can repair it, go for it. Otherwise, use a DSS lower pattern. You may have to buy a whole DSS box and then use the DSS box for parts. If you had both the DSS box and the original repaired box repainted, then you could use what parts you needed to make a functional and original appearing airbox.
5. To repair or to replace original "plastics," that is the question....... ! i guess you could evaluate the integrity of how the repair outcome would be, based on how badly the part is cracked/broken, as well as how much it would cost to repair vs replace. on 232 i had no original early airbox nor late box for that matter. So, went to DSS. Ditto sidecovers. i don't know if DSS airbox and Yamiya airbox are same in quality. I can say, i would always use the Yamiya side cover over DSS and the DSS airbox is less money than Yamiya box. The DSS box works very well, is made of polyurethane, so must be cured under UV light to remove mold releasing oils before painting or paint will not adhere.
6. the mirrors that came on maybe the first 300-400 vins had 11mm stems, then went to 10mm stems. the mirror backs that hold the glass, these mirrors that came on the bike off the assembly line have 2 logos, "HM" and "MS." Later replacement mirrors, not certain of production date, had only the "MS" logo. (even early K1 mirrors had the "double logo" mirrors, of course not acorn nut type.) (KP has dis-assembled these mirrors and had the metal backs re-chrome plated.)
7. Suggestion - when you get 248 home, print off the BB thread titled "86 Distinctions" and compare what you find on the bike to what you note on the list of 86 distinctions. Then ask post your findings or ask questions accordingly.
8. Rust on chrome plated parts. i have had great luck using Naval Jelly, available in hardware stores. Naval Jelly is very viscous dilute solution of phosphoric acid that clings to the part it is applied to. The application time varies depending on severity of rust, but rust will be removed, leaving the bare steel. On badly rusted gas tanks, i have left Naval Jelly in the tank for up to two weeks. Some guys like to use muriatic acid, but the potency of muriatic acid, for rust removal and attacking good metal as well, scares me, especially if the metal is thin. Even using Naval Jelly, if there is a pin hole and the acid is used long enough, the pin hole will be revealed. That is a good thing, of course, no one likes to find a pin hole from rust in their tank......... ! But, better to know before the paint is applied, than after........... !
9. Don't be sorry for your questions, you are asking good ones. Keep asking them. We need this type of discussion to keep things alive.
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Thanks Steve
Great info. I read the 86 differences thread earlier and will certainly do as you suggested. There are a couple of terms I'm not familiar with but I'll ask when I get to them.
As for plastic/resin type repairs, I love that stuff. Like I said I was involved in a couple of Vintage Vette restorations where we wanted to keep the original parts intact. The fun part was the built in factory imperfetions had to be duplicated which were not there on jobber panels etc. It was great fun and one of our cars, a 64 split window coupe won a show at a concourse level. Very gratifying. If you ever come across a 63 or 4 Vette look near the front of the rear quarter panels. If they look like someone did a bad job of glassing them in, that was GM. If it's dead straight that's someone depreciating a valuable unit with bondo and block sanding. That's the stuff I'm talking about.
So having said all that I would be curious as to the imperfections in an original unit. Can you make these things too perfect? I know painters will skim tanks with bondo and block them out to get them perfect. Is that really desireable or if you have a perfect tank do you just strip it, prime (not filler primer) and do your paint?
You don't have to answer these questions however this is that type of stuff that gets my interest. When we do cars we even go to the lengths to put any production "check markings" in the correct places of the unit. These were usually done with grease pencil, paint dabs of certain colours etc. In my experience with Brit restorations I have never researched or done any of this. Should I go ahead with this unit the build will be as close to "correct" as I can make it, including assembly markings etc. if they were used and we know what they should be.
I guess I dive in with both feet which is why I'm knee deep in a Triumph custom I'm working on. It's killing me just because it had to be one of a kind and different!
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Steve
You said those plastic parts were made "nasty, rotten, brittle material. Has the material been identified here? It tests like polyurethane but I could be wrong. I had a friend who had a better sniffer than me who could tell me but he's no longer around. I see three types of repro side covers. Fibreglass reinforced panels, ABS and polyurethane. It would appear the latter would be a better choice for a more "autentic" build if I'm correct on the original substrate.
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Hi
I would definitely restore the airbox...if just for the provenance or showing.....not sure what your intentions are.....but if you plan on riding it get a set of repro's for riding. That's what I do.
Steve
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Goodness, another Steve! Yes, I agree Steve. I have been doing a lot of reading, and whether I restore this bike or sell it to someone else I think the original parts should be salvaged and repaired where possibe, especially the early air intake box. As for the side covers from a collector point of view is it better to have the originals repaired and re-finished or purchase the best repros money can buy? I would imagine finding NOS or even near perfect used covers would be almost impossible. These are the things I will look at over the next while and make my decison on what to do with the bike after I finish my fact finding. Thanks for chiming in Steve. I'm here to learn.
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Hi
If the material the headlight shell, side covers and airbox are made of polyurethane, it's not the PUR i am familiar with. That being said, i am no plastics expert, but this material Honda used seems more brittle than flexible and cracks fairly easily when used. I am not aware PUR has these characteristics and the PUR i am familiar with does not degrade with age like the material used by Honda.
I agree w/ Steve F on saving the airbox, best suited a good shelf item or fit for a museum bike. Getting that restored orginal airbox assembled and mounted in place without breaking it in the process is entirely possible, but the stress of being mounted, heat and gasoline vapors will likely make it crack in time. Wes Anderson told the story of just bringing his long stored sandcast machine into the warm daylight sun, came back and there were large cracks in the box.
I am not aware the "nasty, rotten, brittle" material has been identified. A very reliable, knowledgeable body man i know, was unable to say what the material is.
NOS sidecovers are *not* impossible to find in the desired color, "only" about $500 for a set and a NOS early airbox will be a long time a findin' - likely never. Even if one decides to buy a set of NOS covers, then are you going to be able to live with the ink stamp date ? e.g., 548 likley built April 69. Pretty certain bet NOS side covers will have an ink stamp date well later into 1969, even 1970. I have heard details like this drive purists mad..........
So, therefore, to my way of thinking, one is pretty much relegated to using repro body parts, unless one is lucky enough to have a bike with solid original body parts -or- has access to a cache' of NOS OEM parts that have the appropriate ink date stamp to month/year of a particular machine's manufacture.........
The material the Japanese used is not fibre glass. Nor are there markings on CB750's such as used by inspectors on automobile assembly lines. About the only 'inspection' marks on a CB750 that i am aware of are the ink date stampings on body parts *and* on inside of engine covers and cases. The other assembly completion marking i am aware of are the yellow paint dobs on certain nut and bolts. Further, i am not certain Honda was dabbing yellow paint on the sandcast machines, it is possible this yellow paint dobbing came along after sandcast production era. I am not aware of anyone who has the exact font to replicate the font of the stamp used on these sidecovers.
Seems, with this sandcast restoration 'business', there are always compromises to be made in the consdiderations to replicate "original."
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Yes Steve, I understand what you're saying on the polyurethane. It certainly doesn't have the characteristics I have seen in a polyurethane product used today. It does however fall into that category when I do a burn test on it:
It melts when touhed by an orange hot object so it is a Thermoplastic.
It burns (yellow flame) and ignites in seconds. (less than 10)
It does not drip while burning. (I didn't test with a large piece though)
Black, almost sooty smoke
The smell of the smoke is nondescript.
To my knowledge those are characteristics of the polyurethane family.
Like I said, I may well be wrong and the melt/burn/sniff test is not perfect. My old friend was far more skilled at it than I. My last years working were with one of the major auto makers and I worked in the body electrical area, working closely with engineering. I was onthe technical side and kind of fed the problems over to them. I'm not even sure who is left up there but I might make a call and see if they still run a lab in Canada. If they do maybe I can get this stuff analyzed. I agree, it's a strange substrate and it will bug me if I don't find out what the heck it is! I thought it was like bakelite at first, until it melted! I'll see what I can do.
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Wayne,
Thanks for the informative post !
Will be great to hear more from you.
I appreciate your enthusiasm for research
Like i said, i am no plastics expert. Certainly this old material could be a PUR substrate.
I only have some experience with PUR used over th past 10 years, including some PUR welding, but beyond this, nothing more.
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Side covers get my vote as made from ABS. My painter, now retired did mine and was a long time plastic welder, probably one of the first around in my town. He did some crack repairs for me and immediately identified the material as ABS. His specialty was bike repair and painting and told many stories about different plastics used in fairings etc. Many of the later bike fairings could not be plastic welded and one he mentioned couldn't be welded or glued. But I do remember being very adamant about the side cover material being ABS. I think the chain guard was nylon. KP
PS. These are good discussions
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It could be ABS. ABS will drip when burned. This did not but like I said, I only tested a small piece so maybe it wasn't a valid burn. The smell from burning ABS is Acrid. I didn't find this acrid at all but then again, my sniffer isn't the best! ABS will burn yellow with blue edges. I tried three times as I was looking for this. No blue.
That's not saying the boys at Honda didn't come up with some kind of ABS based substrate. With no identifying marks on plastics back then I'm guessing the only way to find out is to test. I have already sent an email to an old friend from work to see if the lab at Engineering is still operational.
Where I'm going with this is, if we figure out exactly what this stuff is then perhaps it can be better preserved. For example if a good side cover were stripped, could a chemical be applied that will re-activate the binding agents in the substrate thus bringing it back closer to it's original composition. It might be a stretch but these things aren't getting younger. I find this stuff intruiging, even if I decide not to do the restoration. I'll keep you posted.
Does anyone know where there might be a picture of an original set of sancast side covers. (inside shot, never re-finished) I'm curious as to the amount of overspray the crept to the mounting posts and the inner part of the cover. (if any)
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Mabe it was PVC he said. It's a fair number of years back but we are talking 40 years ago and what was ABS then could be chemically different today. One thing is for sure, heat and sunshine makes it very brittle and prone to cracking so maybe there is a clue in that. Manfred Doring may have a picture of the reverse side 8) KP
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From what i know PUR has been around since the late 1930's.
I am sure, as Wayne has said, there have been newer and different substrates developed since PUR was first created.
From what Wayne is saying, his preliminary testing is not conclusive, but appears to support the sidecover composition has some of the characteristics of being in the PUR family, but not all the characteristics.
Considering there are different substrates, the chemicals used within the PUR family to make these sidecovers then may not be the substrate of choice used today, if Honda were still making these side covers.
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I have made my decision on what to do with the bike. I'm going to keep it and give it my best shot. Since I will want to ride it a bit to some local "show and shines" it won't be a perfect restoration I'm sure...but who knows once I get started! I'm already making space to keep it in my shop once it arrives on Sunday. (there was a delay getting it moved) It will probably go kind of slow as I have a custom on the go that I have to get completed. I figure I can get the Honda stripped down, tagged, photograped and documented when time permits.
I put together a quick website where I will store details of the teardown and assembly. It's not inteneded to take anything away from this site, I just have lots of server space so I thought I would put it to good use.
http://1969cb750sandcast.com
I know I will have lots of questions, the first being about frame re-finishing. I have seen some bikes powder coated, some painted and some left original. Mine will have to be refinished as the paint is off in some areas.
The guy who does my custom paint work recommended a guy who came back with what I thought was a very reasonable quote to strip and powder coat the frame. He did ask though, chemical stripping or bead blasting? Your choice.
So what are thoughts on frame finishing for the type of build I'm doing? I know powder coat is more durable but if I'm going to this length should I go with something closer to what Honda originally used?
Does anyone else have their builds documented out? I see World documeneted a one day build online but they don't talk about re-finishing tecniques in any detail. He did a nice job though!
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At VMD, Vic gave 3 one hour long seminars on restoration considerations, processes, finishes, plating, etc.
My self, never been a fan of powder coating and use it only on select applications. I know p.c. can look fantastic from a quality provider. I don't like p.c. because it WILL chip (sometimes very easily with the "tink" of a slipped wrench or stress of tightening a nut), it DOES get microfine scratches from cleaning. Of course, paint will do that as well, but at least paint has a "green" period where it will not chip or twist of as readily as p.c . Just MY experience/opinion....... !
Other than that, the outcome of the restoration is 100% in the eye of the owner/restorer. Of course, many of us have found what works besrt for us, paint finishes, plating, etc.
Wayne, just keep asking questions and then ultimately follow your desire.
GLAD TO HEAR YOU HAVE DECIDED TO KEEP THE BIKE !
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I would never use PC on a classic bike. A good nomal quality painting will be good enough for a bike that not beeing used in every weather, and it looks better than PC. It will also be much better than Hondas original painting witch was bad quality without base coat.
Karsten
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The bike is at home in my shop! Finally! I have started to upload pictures to my web site showing the current condition of the bike, the good, the bad and the ugly. IMHO it has all of the above attributes. Nothing time and money can't fix! I have started to soak some of the fasteners with Liquid Wrench in hopes of easy removal when the time comes. I have had great luck with this product in the past.
I have corrected the numbers on my site. The bike is actually:
Frame - 1000576
Engine - 1000748
I thought the frame read 578. My apologies.
I read EVERY thread on the forum here and have learned a lot so far. Still a long way to go. I read about the engine cases paint controversy and it appeared that Vic World put that issue to bed. For the record though, 748 exhibits all kinds of engine paint still intact. The engine is corrosion free in many areas as a result.
For now, I'll get my pictures posted and we'll go from there. There seems to be a few curious things about the bike but we'll get those figured out along the way.
If there is something specific you would like to see let me know. I'm keeping the camera on charge.
Lastly, the tank appears to be in excellent condition so I have a mini web cam with led lights on the way so we can explore inside! I'll post the movie file on my site. Yes, I will fill it with an inert gas before I stick that cam in there!
Any feedback or observations are very much appreciated.
Almost forgot! The right side cover seems to be in good shape. The problem is, the rubbers are very dry and hard so the cover does not want to come off. I didn't try too hard. I sprayed some WD-40 where I could. Anything else that might help? I would hate to break a mounting tab off.
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Wayne on some of the sidecover tabs you can reach around from the backside with one finger & push out on the tab so you don't snap it off. A little heat from a blow drier on the rubbers also helps. Do your self a favor & replace the old hard rubbers asap
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Thanks donzie
I'll give that a try. All new rubbers for this old girl will be on the shopping list.
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To loosen and free the very worst of rusted parts I swear by Aero Kroil penetrant by Kano Laboratories - http://www.kanolabs.com/
Aero Kroil penetrant is a tremendous aid to liberating galded and seized parts.
Ask Allan Landry what he thinks of Aero Kroil.
Silicone spray might be worth a try in removing side covers.
Wayne, always try sourcing through Honda before paying excessive prices on ebay or elsewhere. I have been recently able to obtain most any engine and chassis parts, exluding such items as gauges, fenders, tanks, etc. Items such as new side cover grommets, no problem.
Looking at your sandcast webpage, picture appears your petcock is the early short neck. As far as we have been able to observe, the last frame vin for the short neck petcock is 1937.
It's interesting, your tank is the 17 litre later type........ Interesting, because if Steve Frampton sees this and can jump in, if i remember correctly, his #745 has a 19 litre tank on it.
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I'll see if I can get some Aerol Kroil, thanks Steve.
I made the same observations on the tank as well Steve. It does have the early Fuel Tap, but a later tank. When we took the tank off prior to moving the bike he even commented how it was the original red underneath. He said they didn't even remove the tank when they painted it. That was evident. The same with the headlight pot. There is overspary all over the front. (it may have preserved some of the lower brake line fittings as they are covered!)
It aslo has early 2 hole Air Box
Early straight fitting front brake line
No fill line in Master Cylinder
Horizontal cut rear brake lever
The list goes on.
It does not have the "28" Carb's on it. Is it possible that if 748 was taken for a Carb recall that Honda would have changed the tank as well? I know there were throttle cable troubles with this unit early in life. Even now it is broken.
The oil filter housing has 7 cooling fins. It has a 12 MM bolt head. I'm assuming from that that either someone cracked the originial and replaced it or Honda performed the Honda Service Bulletin CB750 #13 when the bike was in for service. I'ts stuck so I couldn't get it off for inside pictures. I'll try again after a good soaking.
I'll keep posting pictures as time permits. As well, I'm going to see if I can getin touch with the original owner and see what he remembers about the early days of this bike. My friend said until he re-located about 8 years ago the original exhaust was hanging in his garage before he moved! He put the Jardine headers on almost as soon as he purchased the bike.
Thanks for the parts tip Steve. I have already forewarned the parts person I know at the local Honda/Harley dealer that I would be driving them crazy with this bike! I do intend to buy what I can from Honda.
I put a couple of local ad's out in the event that there might be some "jewels" in my area. Received a couple of responses on some NOS items. They just have to get back to me with numbers. I guess the next thing is, I need a parts manual so I can validate before I buy.
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Hi....I had mentioned to you Steve, at the VMD, that the 19 litre was actually on 325...not 745. 745 had no tank with it.
Steve
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Hi Wayne, the tank looks to be the correct original one - according to KP, if the short neck fuel tap is used on the tank, the area where the tap bolts onto is actually more pronounced than later 17litre tanks. Normally that shouldered area has no pronounced shoulder or step where it blends into the front of the tank. Wayne, your tank has a pronounced shoulder towards the front of the tank. Mine is the same - short tap, shouldered area (VIN 1927). I think it would be easier to see what I mean in the photo on the website comparing the 17l and 19l fuel tanks....
Regards, Steven V.
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Hi Wayne, the tank looks to be the correct original one - according to KP, if the short neck fuel tap is used on the tank, the area where the tap bolts onto is actually more pronounced than later 17litre tanks. Normally that shouldered area has no pronounced shoulder or step where it blends into the front of the tank. Wayne, your tank has a pronounced shoulder towards the front of the tank. Mine is the same - short tap, shouldered area (VIN 1927). I think it would be easier to see what I mean in the photo on the website comparing the 17l and 19l fuel tanks....
Regards, Steven V.
Steve V is correct. The tank you have is the 2nd generation wrinkle tank and has the correct petcock as well. The earlier 19 litre tanks were superseded at VIN 746. See Steve (Rivers) Swan's post
http://sandcast4363.proboards.com/index.....play&thread=308 :-* KP
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Steve Swan's memory is not like a steel trap. Most of what i write on the website, i believe to be 99.9% accurate, i try to not write crap. The other 0.1% i am wrong.
Much of what i wrote in "86 Distinctions" came either from some bike i observed, had written down, the website or my memory of what i someone told me, case in point, please read the next sentence........
Please note Steve Frampton's above post gently reminding me it IS #325 which came with a 19 litre tank - 745 came with NO tank !!!!
I had written "86 Distinctions" for something to be handed out at VMD and was feeling somewhat certain from a conversation 3-4 years prior with Steve F, his 745 came with a 19 litre, which is not the case. I forgot what he told me, 325 HAS the 19.
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I think as I identify a part as being "correct"or "incorrect" I will put a list on the web site for 748. It will help to clearly see where I stand as I start down the road with this project.
So, it looks like the concesus is that it has the correct fuel tank and Fuel Tap.
I would aslo say based on the pic's of Sandcast Gas Caps that the cap on 748 is also correct.
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Wayne,
Thanks so very much for your enthusiasm for the machine and your fastidious manner of notation.
Really is kind of an archeological dig of sorts !
Your website is great. Keep up the good work.
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Thanks Steve
I will continue to post images and ask questions right through to tear down time and re-assembly.
In looking at the rear fender, it has two mounting holes, the wiring pass through holes and then 3 holes around the bottom that appear to be for a mud guard. They look stamped rather than drilled. Should they be there? The fender looks salvageable otherwise.
Here's a link to the pic:
http://1969cb750sandcast.com/images/rear_fender_view.jpg
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The tank fitted, and "short" gas tap are identical to those fitted to my #1120 (raised pad underneath for the short tap, four indents corresponding to the carb tops, 17 liter, etc). I would suggest this to be definately correct / original.
The three holes around the lower of the rear fender - the centre one is for the cone plug (a rubber stop intended to cushion / support the lower of a license plate). The two side ones I have never seen before on a sandcast and wopuld suggest them to be non-factory additions.
Nice find, and great pre-teardown approach to the job.
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Thanks hondasan
The rest of the rear fender is in great shape. Hopefully we can neatly close those side holes up and let the chromer work his magic. Is what I have the "3 hole" rear fender I have seen others refer to?
I felt with the web site it would at least let me get intimate with this project prior to any major wrenching on it. Hopefully the documentation wil help others and perhaps clear up a few gray areas that may exist in the "sandcast" world. For me that would be as rewarding as the finished project.
If anyone has a period correct parts manual they could zerox for me it would be much appreciated. Just let me know what your time, paper, effort and postage is worth and send me a message.
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I guess it could be described as a "3 hole" fender as opposed to the later K1 type "4 hole" fender.
Sandcast has just two fixing screws for the lamp bracket to fender, the third hole being for the lamp wires to pass through, and will have a rectangulat re-inforcing piece spot welded inside the fender with two "captive" nuts.
The K1 uses three fixing screws, + hole for wires (hence 4-hole) and has a triangular re-inforcing piece inside the fender - and of correspondingly different lamp bracket and rubber cushion.
Chris R.
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Thanks Chris
Mine does indeed have two mounting holes and a third for the wiring. It looks like there is a fourth hole in my pictures but that is just a shiny chrome area where there was a recess in the rubber gasket.
So, it looks like I have a "correct" rear fender in need of some minor repair before chroming!
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Yes, the mudguard (fender to you uneducated rabble ) ;D looks correct KP
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lol @ rabble. Over here KP the mudguard (or mud flap) would be the rubber thing that hangs off the fender, which is probably why my fender has two extra holes at the lower outer edges. :(
It would sound funny if you hung a mud flap from a mudguard?? ::)
Maybe those extra holes were a Canadian content option for the snowy winters. Option BAM. Big Assed Mudguard?
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Steve Swan asked me to locate the case date codes if I could. I found the top one OK, just to the left of the green dot. It is:
E-1
415
Can anyone help point me to the location on the lower case? This bike sits kind of low. I just realized there is no centre stand! On top of that I just had laser eye surgery and have to be a bit careful digging around.
The only number I see on the back side of the lower case appears to be 130. It is stamped, not cast like the upper number.
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If it works out ??? , picture of date on lower crancase of engine #338.
This motor has NO DATE on the upper case - it seems that at this time, upper cases were not dated.
All you guys with early serial number bikes (in fact any and everyone), please check date information and location so we can update the VIN directory.
Thanks - Chris R