Honda CB750 Sandcast

Oil filter cover

chrisnoel · 63 · 24688

mb124

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Hi Steven ,
I had a closer look at my finned , unreinforced covers .
1st cover  off VIN5120/E5306 : 14mm bolt ,painted silver by myself .
2nd cover , off Ebay : 14mm bolt , silver paint
3rd cover , off Ebay : 12mm bolt , silver paint
None of these covers has a casting number on either side of the 12  o`clock locating rib .( easy identifying point without removing cover from engine )
I also have 2 off covers with "2" cast in , as shown as the replcement cover from Honda in Service Bulletin #13 . Bolt changed from 14mm to 12mm together with "#2" cover.
 This "#2" cover is also shown on p.17 in the #97 restoration. 
Strange : the mating locating ribs to fix the oilfilter cover are present on my VIN1161/E1306 engine case ( not on #97 ,see p.17 ) . So it means engine #1306 was already prepared for the ribbed cover .(I have a Yamiya cover fitted )
I think you are right in assuming that all later sandcast`s was fitted with the ribbed , unreinforced cover (no cast number ) , silver painted , and 14mm bolt .
Amazing how much archeology that can be applied to an oil filter cover...

All the best

Geir


markb

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This "#2" cover is also shown on p.17 in the #97 restoration. 
I looked by I couldn't find the #2.  Is it on the one that Chris shows or mine?  Where is the location?
Thanks,
Mark
Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


mb124

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Hi Mark ,
it`s shown in the first picture in the post "Reply #242 , Feb. 19.2011 " , page 17 .
You can see the "2" cast into the right of the locating fin on the oil filter cover .
This is exactly as shown in the Service Bulletin #13 , 1/26/70 . Also , I have 2 of these covers (finned , internally ribbed, "2" cast )
Many thanks for sharing the #97 story ,  outstanding presentation .
Best Regards
Geir



hondasan

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Service bulletin number 13 refers to engine numbers 1783 to 9554 as being the range for which the internally reinforced finned bowl was to be applied.

WHY 1783?

If you look inside an original round bowl, it is cast in such a way that there is no sharp corner inside the bolt boss which would be susceptible to cracking in the same way as the first finned type was (in fact there is a nice cast radius, which provides effective crack resistance). For this reason, there was no need to replace original round bowls with later type re-inforced finned bowls. Therefore you could deduce that engine 1782 was the last factory built engine likely to have been fitted with a round bowl, based on this particular service bulletin.

UK parts list number number 4 however identifies a change from the first "000" bowl to the "010" bowl from engine number 4149 (also a change of the filter bolt at the same number) - Honda literature is always accurate of course!. Owner observations also suggest engines later than 1783 to have had round bowls - I'm sure they all have perfect memories where detail and events of over 40 years ago (which would maybe not have been of such interest then as now) are concerned!!!!?

I'rm with Steven regarding making judgements regarding fact on this subject, as there is contradictory information. We all have to make our own minds up, taking account of the available facts and observations - and the more people that contribute, the better for all.

Only three pieces of information I can offer - #302 (E338) came with a round bowl / 14mm bolt. #5298 (E5192) came with a fiinned, unreinforced and internally CRACKED bowl, #86xx (E8550) also came with a finned and unreinforced bowl. I BELIEVE all three to have been original, but can't know that for fact as I was not the original owner of any of them.

That's my two pennorth!

Cheers - Chris R
Chris R.
302/338


kp

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KP, you're entitled to disagree- my email wasn't stating anyone was correct or not.  We are all trying to add more info in to knuckle down a range.

I also seem to remember you swearing that engine cases were never painted at one point but the more input we got by raising the subject, we realized that they were.
Steven, Hmmmmm!  I don't ever recall "swearing" that engine cases were not painted. Maybe you can direct me to that post. I do recall starting a post asking the question but wasn't aware I posted a comment "swearing" they were not painted or are they your words Steven  ::) Mind you, I'm happy to take it on the chin if I'm shown I did make that statement. And if some future evidence emerges that confirms the round filter was ceased in the 1700 range then I'm really in credibility trouble.
Also, my post wasn't saying you were incorrect, rather I was conveying that I don't agree with the email content you posted from Vic. I hope he was happy for you to post his comments as I certainly wouldn't want my private email correspondence posted for all to see especially when some disagree with the content.
I might also clarify that I stated "Fact and no ifs' and buts as far as I'm concerned". Before members begin to lecture about how one uses the word "fact"  my suggestion is to read the complete sentence rather than a few words. I've said this before, it is difficult to convey in words what would otherwise be conveyed in verbal conversation. I have accepted that round filter covers were part of the kit on sandcasts engines, at least over 4500 so for me I am accepting this as fact. If others believe otherwise then that's their right.
As for Honda service bulletins ?????? Seems yet again they leave us with questions.
I will close by posing this question.
Do we all agree that the literature states sandcast engines were fitted up to VIN 7414.
Yabba Dabba KP


vnz00

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Hey KP, 'swearing' Ill admit are my words as I couldnt remember your exact words at the time:
http://cb750sandcastonly.com/smf_forum/index.php?topic=138.0

My dealings with Sandcasts is limited to 3 engines and whilst I've always believed the cases weren't painted...

Not about sticking to you KP, just an example (which Im sure we could all give) based on limited experience at the time, which we have all had moments of.  Conflicting information is actually what I am after so we can challenge the current thought and establish a 'norm' based on practice rather than literature.

I introduced my email to Vic asking for his experience to help the wider sandcast forum community so I did consider it acceptable to post his comments to help us all.

Your last point is a bit of a loaded question - yes literature states that, but I believe there is evidence here of a later engine number having sandcast cases.  This is just another example of literature and practice differing, presumably to get another bike 'out the door and to the hungry customers'.  Just like Aus and Jap K0's having a later VIN than literature states.  I have no doubt this same irregularity applies to the oil filter mystery too.

I agree with Chris R's statements regarding the round oil filter housing not being targeted for replacement as it may have been considered a non-defective part. I dont think honda were aiming to replace every part which was considered non-defective with newer versions of the part as Marks bike would not be as original as it was.  Just that in so many cases with production bikes, the practice and literature differ.

The service bulletins dont pull numbers out of the air - I have no doubt that they are based on records of some sort at the time (i.e. Honda may have produced X amount of round oil filters, fitted them religiously to Y number of bikes, kept z number of parts as spares which filtered on to the production line as new parts production couldnt keep up with demand, and Honda based service bulletin and parts bulletin on either of these figures, not on actual practice where there could have been a mix of parts used).  When parts were superseded to later parts, it was quite common for Honda to modify part manuals to say that the part, even if different, still applies to all prior bikes.

There are basically too many variables to this equation - there is a 'practiced norm' and there are the 'exceptions'.  But just because someone says I saw a round filter on VIN 12000 the other day (which I did) doesnt mean it was the norm, and that all bikes up to that number used them even if it was original to the bike.  It could be the case that even up to 4500, they were still used but as an exception rather than the norm.

« Last Edit: September 06, 2012, 08:20:36 pm by vnz00 »


Steve Swan

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Been resisting posting; I've allowed your remarks to get the better of me.........   ;D ;D ;D ;D

Dad bought 4779 new; September 30, 1969.  Later on, I remember me doing one oil change in particualr on that bike; dropping the cover into the drain pan because it was hot and slippery; unsuccessfully trying to pick the damn round, hot, slippery thing out of the drain pan.  I can still see the cover in the pan.  The date was late September 1970, the place was the Union College parking lot, beside the Prescott Hall men's dorm.  The men's dean was making me put my motorcycle into storage for the Winter, because i was a Freshman and Freshman men were not allowed to drive vehicles until they successfully passed their Freshman year.  So i was getting ready to put my precious Honda 750 into storage, changing oil and giving it a very thorough cleaning after riding the bike all summer including the trip i made to California earlier in May (as well as gravel roads for trips home.)  When i was preparing to change the oil, Ted Hansen had just parked his pea green panhead Harley and came over to watch me.  When i dropped the cover in the drain pan, Ted had a small laugh at my expense.  A few days earlier, i had just bought a Snap On impact driver (which i still have) I paid $32 for that driver.  To give the bike a thorough cleaning, i had removed the exhaust and used the driver to remove the exhaust flanges, after i had changed the oil.  I remember noting oil leakage at the head joint and burned oil around the flanges, which i wanted to clean before it got completely baked on the fins, especially since the bike was ging into storage.  I remember a few days before this oil change, as i was getting ready (dragging my feet) to put the bike into storage, i discovered the flanges were held on by screws i could not remove with a common screw driver and telling the dean i needed a few more days before i could get my 750 into storage, because i was waiting on the special tool (the Snap On impact driver.)   The odo on my 750, had just turned 18,000 miles.  I remember telling Ted, when he was watching me change the oil, that i was putting my 750 into storage and asked him, when i was done working on the bike,  if he could give me a ride to the garage that was about a mile away from the dorm.  I remember Ted following me to the garage, waiting for me while i took the battery out of the bike and my heavy heart as i rode passenger behind Ted on his Harey.  When i gave the men's dean the keys to my bike, i remember thinking to myself how happy i would be when i was an upper classmen like Ted.  Some memories leave indelible impressions, the privilege of that "last" oil change is one first hand experience i remember well, which is mine and is what it is. 

I remember when Ed Mathis brought his new red 1971 750 to college, June 1971.  I had my 750 back, i successfully completed my Freshaman year. Ed and i compared features between his brand new bike and my "old" bike.  We were both serious farm boy motor heads.  Amongst a number of differences i remember between the two bikes, i distinctly remember wishing 4779 had a finned oil filter cover like Ed's bike.  I also remember liking Ed's steel cased gauges, because i did not like "cheap plastic."  I remeber not liking his plastic side cover badges, but liking the shape of his side covers.  Ed and probably spent at least two to three hours on more than one occasion, comparing our bikes.  I also remember 1st gear rolling "drags" with Ed, no matter i rode my bike and he his or we traded, on a number of occasions, my bike would always beat his by half to one bike length.  Most probably because my bike had, by that time, had a little under 20,000 miles and his bike was still new.

Of course i don't remember every thing.  Who does.  But what i do remember from my experience, is nothing i've made up, embellished... or forgot. Or, will swear to or argue.  I can tell you all sorts of features, details, on more than a few of the 70+ motorcycles i have owned/ridden/rebuilt/restored in my day.  Certainly, some of the motorcycles and their features, i barely remember or cannot remember at all.

The Honda 750 Four is not one of those motorcycles. 

For a farm boy, who's father was a mechanical engineer, successful salesman of his inventions, of which he built the first examples with his own two hands, i was taught (and expected) to pay attention to detail.


vnz00

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Steve S also confirmed his bike came with one from new, and I don't doubt that.

No doubts to your observation Steve - just saying we are short of info and we can do with more first hand accounts :D


Steve Swan

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10-4, Ozzie mate !  Just thought i'd include the detail to my past statement 4779 had a round cover.......  

Agreed, would sure be nice, if more people, with more exposure or different experiences, would share.  It's hard to beat first hand experience.  We all still stand to learn alot more than we already know.    

Alot of what we say or think we know, cannot be proven.  Our conclusions usually must be arrived at by deductive or inductive logic.

Would be nice to share that info that supports that logical reasoning.

Keith has great first hand memories, having worked for a Honda dealer during that time period.  

Marty has some first hand experience also.

Definitely welcome Vic World's participation.  Wish he could come on, once in a while.  As an example, some of us (myself for one) had mistaken belief about crankcase surface finish.  Vic was helpful in clearing that up.   Our web page supports World Motorcycles.  

Another topic, as i may have mentioned or alluded to sometime earlier, i worked for Olson Brother's Honda Triumph, before i left for college, June to early August, 1970.  One of my jobs was removing and setting up the small bikes out of the crate and helping remove and dispose crating for the larger bikes.  What i remember about 750's, we had not a one new 750 unit come in during that time.  

I remember the red 'mate' to my blue-green bike coming in for a service and really really liking that red.


kp

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Yes Steven, I thought they were your words. Maybe you should choose your words a little more wisely and avoid the need to recover. I would also suggest you show the entire sentence of my post of some years ago as your attempt to try and recover some lost ground by posting a one liner also hasn't cut it for me. Am I a little miffed. You better believe it as I always try and contribute to the debate rather than taking pot shots at an individual. I'll make no further comments on this point
As for my closing comment. It was through my persisting in following up a rumor that there was supposedly a sandcast engined CB750 located in France finally brought to light some actual photographs of the said motorcycle. This then led to some remarkable disclosures ie: that of at least 5 such examples exist. My point is that the the belief that VIN 7414 was the last bike fitted with a sandcast engine was busted with this French find.  Just one exception blows the norm whichever way you look at it. Just one bike after VIN 17XX fitted with a round oil filter housing blows the accepted norm, just one late numbered crankcase with a small engine number pad blows the accepted norm that they belong to early VIN bikes. I remember some years ago I was challenged when I suggested there were several different rocker covers used on the K0 model. That information was first suggested by Andy Morris many years before but nobody thought it was correct. We now know there are at least 2 different rocker covers used on the sandcast and comprehensive information is posted on our site. Nothing is sacred as for a sandcast having this or that and I will repeat my comment that service bulletins are ???  ???
This is a closed book for me now
Yabba Dabba KP


markb

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Hi Mark ,
it`s shown in the first picture in the post "Reply #242 , Feb. 19.2011 " , page 17 .
You can see the "2" cast into the right of the locating fin on the oil filter cover .
This is exactly as shown in the Service Bulletin #13 , 1/26/70 . Also , I have 2 of these covers (finned , internally ribbed, "2" cast )
Many thanks for sharing the #97 story ,  outstanding presentation .
Best Regards
Geir
Thanks, I was confused and thought the #2 was on the smooth oil filter cover.  So the #2 finned cover is the latest (last) version of the finned cover?
Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


Steve Swan

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I just want to say i appreciate very much and we need very much everyone's observations, this is how we get a closer idea waht these features of the sandcast were from the factory.

KP, I and Andy Morris were at this "sandcast thing" long before the website went on line Dec.2004.  And, i am only saying this because long befor KP, Andy and i were thinking of things sandcast, there were other people long prior, thinking talking things sandcast.  All i know, when i got reinterested in the 1969 CB750 around 2000, i started networking immediately, asking questions, wanting to learn more and as much as possible.  What i quickly figured out, there were the same personalities who knew about sandcasts as knew about Indian 4's, Chief's Scouts, Excelsiors, Henderson's, Ace's, ohc Britich singles and ohc British singles and twins of various configurations.  (Human nature does not change.)  These examples are:  1.  Guys who literally slept, lived and breathed some of these marques.  Some of these guys were the most humble type, always willing to share what they knew and would sell a part they did not need at a price that gave someone else a chance to get their bike on the road.  2.  Guys who slept, lived and breathed some of these marques and would share little or nothing about what they knew, sell litle at infalted prices or nothing at all.  Seemed they wanted to keep what they knew secret as possible, for whatever the reason.  Or they were the guys, after you heard them talk, were people one avoided or had as little to do with as possible, for whatever the reason.  3.  Then, there was/is the spectrum of people in between.  Kind of the same thing as those who get involved, those who stand by and those who benefit from what the involved people do.  Am sure you've experienced some of what i am describing.

What i am saying is this:  all we are simply trying to do is learn through discussion and debate.  We got a little bit of that over the topic of 11m stems.  Of their existance, more than just myself learned this detail from Vic at the 2009 meet.  Seems sometimes the debate and discussion gets  a little strong, perhaps heated, but that is where we hopefully can park our ego at the door in the spirit of fellowship and desire to share what we learn.  I've learned little to nothing from guys who share little to nothing.  What this debate tells me is we all have passion about the sandcast CB750.  I for one am damn glad we share that passion.  We're all here to help each other and we've learned alot from each other.  I learned just when i thought i knew it all, there is another guy who thinks or actually knows more than i do.  Over the years, i've reframed that as "we all know different things, let's share those things and have some fun."   I also believe what is in written form can be interpreted or 'sound' differently then when the same information is given in first hand, eye to eye conversation.

So anyway........  sandcasts are alot of fun and i like them because i had one when it came new from the dealer. If i did not care about motorcycles, i would not have the same passion we all share in what we enjoy doing.  Sandcasts are a small, yet enjoyable part of my life.  I figure there is and will remain alot about sandcasts i never know. 

So, let's all share and participate as much as we are able.  That was and remains the purpose of the website, to include all, share what we know and have fun.  That sure happened at the 2009 meet with everybody who attended !


mb124

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Hi Mark ,
it`s shown in the first picture in the post "Reply #242 , Feb. 19.2011 " , page 17 .
You can see the "2" cast into the right of the locating fin on the oil filter cover .
This is exactly as shown in the Service Bulletin #13 , 1/26/70 . Also , I have 2 of these covers (finned , internally ribbed, "2" cast )
Many thanks for sharing the #97 story ,  outstanding presentation .
Best Regards
Geir
Thanks, I was confused and thought the #2 was on the smooth oil filter cover.  So the #2 finned cover is the latest (last) version of the finned cover?
Hi Mark ,
as I interpret it : the internally unreinforced covers were prone to cracking around the oilfilter bolt hole ( yes , the cover on my VIN5120/E5306 has cracks ) .
To remedy this , Honda made an internally ribbed cover with cast mark "2" , to replace covers from VIN1783 ? -9554 . It`s reasonable to assume that bikes after VIN9554 was fitted with these upgraded covers .
Later bikes has higher numbers cast in , I have "7" , "3-1" , "3-2" , probably from K2`s and up .
The #13 Bulletin states " All original center bolts should be replaced with the modified center bolt at the earliest opportunity " . For the covers : " All oil filter cases should be checked for hairline cracks around the center bolt boss when installing the new center bolt . If any cracks exist , replace the oil filter case with a modified case " .
So with no apparent cracks , the covers survived the upgrade , the 14mm bolt didn`t .
Luckily ,some bikes also escaped the upgrade completely....
Cheers
Geir


vnz00

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KP, if you are still reading then we seem to have our wires crossed.

I cut your sentence short because it was more a paragraph but incuded the link if there was curiousity to the subject.  However had I included it, the meaning was still what I was illustrating.  At one point you would not have painted your cases 'prior' to more information coming to light.  I don't see how I tried to recover - I found your original point as you asked.  I wasn't saying you still stood by your original belief.  Just that like many of us, we might do things differently if we had more knowledge at the time we polished this or painted that.  If you still feel I'm taking a pot shot you are more than welcome to take it up with me with a PM.

My point about the 'norm' and 'exception' is that even though there might be an exception, doesn't mean it was the practice (norm) for all bikes up to that exception.  Yes I agree with you - it disproves the parts bulletins or service bulletin accuracy - that's easily done - but it doesn't dictate new standards to restore to until we understand the circumstances more. 

Thanks Gier for that SB info saying that 12mm bolts replaced the 14mm but unless cracked, the finned unribbed covers were to remain in place.  It gives a new possibility for my bike :)

Thanks Steve S for keeping perspective on the topic.

Regards
Steven.



Steve Swan

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Thanks, Steven !  I appreciate that.  I'm trying ! 

But, I will admit, I still do love the drama of a good old fashioned "snot flinger" once in a while myself !

Just ask my wife; she'll tell the truth about me !  Some times I still just take myself too damn seriously.

I'm still eagerly waiting for someone, anyone to post on the "then and now" thread i started under "general discussion." 

C'mon you guys.  Expose yourselves for who you really are !!!!