Honda CB750 Sandcast

Here we go

greenjeans

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I lucked into a sandcast a few months ago.   I have run an add on craigslist for about 5 years now off and on looking for 69-76 CB750s.  I don't really get many good leads, but occasionally, something turns up.  A gentleman contacted me and told me that he had what he thought was a 73 CB750A.   I wasn't interested, but I told him to go ahead and send me some photos and I'd try to find him a buyer.  When I got the photos, I was surprised.  It definitely was not an automatic, and wasn't a 73.   From his blurry photos, I could tell it was an early CB.  I called him back and asked if he could get me the serial numbers and some more detailed photos.  Imagine my surprise when I got the numbers... The frame was a mid 3000 number sandcast.  The motor, was in the 8000 range - bummer, but I thought I still need to grab it.    I gassed up the truck and took off to go get it.  When I got there, I double-checked the serial numbers and was shocked when I realized he had misread the number - it was in the 3000 range as well.  HOLY-CRAP, I found a sandcast!  

After we got it loaded up, I stayed for a bit and tried to find out more history on it.  Supposedly, one of his old buddies had the bike in his barn since the mid 80's.  He had recently passed away and his son ended up with it.  He had no interest in it or selling it.    Years went by and it sat, withering away neglected.  About a year ago, the son had some tax work done by his dad's buddy (the guy I got the bike from) and never paid him for it.  After trying to collect the money he was owed, he offered to take the motorcycle for payment.   That's when he started digging around on craigslist and found my add.   All he wanted was what he was owed - he had no interest in restoring or parting the bike out.  He's a hot-rod guy and was happy to know that I would at least get the bike back on the road partly as an homage to his old friend.   He even gave me 20 bucks off his asking price just so I could tell my wife that I was able to negotiate him down on the price.   Luckily, in this case, the man did not need the money - it was just a matter of principle for him.  He's retired, lives on a beautifully manicured 2 acre lot in his huge dream house and spends his days tinkering on his 1930 model A.  The sandcast was in his way, but he couldn't bear pushing it back out into the weather.  He had no interest in restoring it - just wanted it to go to a good home.

I got home that afternoon and got it unloaded and into the shop.   I read non-stop for the next few days trying to familiarize myself with the nuances of the sandcast CB750.
After closer inspection, I found that almost all of the original parts were there.  The only things I found missing were:  the mirrors.
Everything else, I think is there and original to the bike.    I was able to find the bottom half of the airbox locally.  I'll worry about the mirrors later.  

My plan (subject to change at any moment) is to take one section at a time and clean things up, inventory and photograph things, make the bike safe to ride again.  Mainly a thorough, thorough cleaning and maintenance that needs to be done.   I'll clean the bolts and parts and put them right back where they were.   Hopefully, I will be able to familiarize myself with the bike and it's parts and keep things in the proper place while creating a record of the bike.  That way, I can can ride it around a bit before I tear things down for repaint, plating etc.

« Last Edit: April 17, 2012, 02:45:49 pm by greenjeans »


greenjeans

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Here's some shots of the bring home day.













markb

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What a great story.  Looks like you've got a good one to work with.  I'll be watching with interest.
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?)


greenjeans

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Don't know why, but I always start with the carbs.    I took the carb racks out and got my 4 large coffee cans ready.  Set up the coleman propane stove and got my old trusty enamel pot ready with some water and simple green.   I've rebuilt numerous sets of carbs over the years and I've settled on my method.   Basically, I take them apart, and put each carb and its contents in their own private coffee can.  Then, I boil them in the simple green and water for 10 minutes or so.  This doesn't really get rid of everything, but the combination of heat and simple green removes most of the heavy crud and softens the remaining crud.   After the boil, I hit them bodies with my homemade soda blaster.  A cardboard box, a piece of acrylic and a box of soda - couldn't be easier.   All the needles and jets usually can be re-used.   I went ahead and ordered some float needles ( I hate leaky carbs ) and gaskets and put them back together.     After that, I always go through them again - just to make double sure that all the passages are clean and the float levels are set correctly.   If there is one thing I've learned about these CBs, it is clean carbs make life alot easier.   They just can't be clean enough.







Yep, all the original "28" caps are intact and there.



greenjeans

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Next, I tackled the rear portion of the bike.  I figured I start with the rear wheel and the swing arm.  I took off the rear wheel and took it apart.  I soak all the nuts, bolts and washers in kerosene (the cheapest best parts washer out there) and clean all the rust off them with a brass wire brush that is on my buffer.  Brass is softer than the metal or chrome so it won't scratch things up.   The correct 2-hole hub was in place.  Luckily, the bearings and the retainer were untouched and original.  The bearings seemed too stiff for me so I picked up some new bearings and new shoes for the old girl.    After I drilled the stake marks in the retainer and the hub, the retainers came out very easily.  I got the bearings out and cleaned everything as best I could with kerosene, followed by a water rinse and liberal amounts of WD-40.    I pressed the new bearings in and put the new shoes on as well.











greenjeans

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I went ahead and cleaned all the linkages etc and removed the swingarm while I was in there.  Normally, I would change out the bushings in the swing arm, but this one was rock solid.  The swingarm bolt looked pristine except for the ends that were exposed to the weather.   Again, a thorough cleaning with kerosene, water and WD-40.

Check out how nice some of the "number 8" bolts are looking.







greenjeans

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Now the bad news.....  all of my pipes except for 1 are not serviceable.  Bummer.    I dropped the oil pan and the oil pump and went through it.  Good news there - no water or signs of metal in the pan.   Cleaned up all the bolts (all number 8) and put things back together with new gaskets.

I also took the oil tank and lines and cleaned them within an inch of their life.



Alternator looked fine - looked virtually new.  The clutch plates were stuck together so I got them apart and cleaned them.  I sanded the steels with some 600 grit paper and some WD-40 for lubricant.  I am lucky enough to have a steel table (from my pops) that has been machined FLAT.  I use that table for the steels and things that need to be flat.
I soaked the corks for a few days and re-assembled the clutch.  Should be fine.



« Last Edit: January 03, 2012, 10:08:34 am by greenjeans »


greenjeans

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For x-mas my wife gave me some much needed gift cards to my local Honda stealership.  I promptly used what I had on those to order some bits and pieces.  I have some fork seals, a master cylinder rebuild kit, caliper seal, new timing/points plate, plug caps, fork boots, and some grips on the way.

Yesterday, I was able to take the forks apart and clean the internals.  To my eyes, the insides of the forks looked pretty decent - although one of the fork springs had some rust ??  How'd water get in there ?  The forks came apart much easier than they usually do.   I'm starting to think this bike likes having all the new attention thrown at it, and is trying to help me out a bit.

The trees, guages, and the headlight bucket came off as well.  Good news there as well.  The wiring loom in the bucket, while still dirty and grimy, was left untouched by previous owners - no splices or mystery wires.   All the ball bearings in the headset were there as well - 18 top, 19 bottom.  The races cleaned up quite nicely and are not scored at all. 
I'll post more photos tonight.


greenjeans

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Just another quick update:   I read a tip on this site regarding softening up old seats.   Avon skin-so-soft.   The cover on this one is intact and only has on small crack/blemish on one of the sides.  I'll have to replace the foam, but I think I'll be able to re-use the cover.   I'm going to have a vinyl repair guy repair that area.  It's about the size of a dime, so I think he will be able to make the repair invisible.

I cleaned the cover and have applied some of the lotion.  The vinyl is actually starting to soften.  The quilted/puffy section on the top has returned. 


kettle738

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That tyre decal under the seat......I've never seen one there before, is there anything to suggest it was always there?

Mick........kettle738


greenjeans

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That tyre decal under the seat......I've never seen one there before, is there anything to suggest it was always there?

Mick........kettle738

Just noticed that - I had always seen them on the rear fender.   I'll take a closer look tonight when I get home.  Perhaps that's where they put them on that first bunch.


Steve Swan

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I'm not aware any sandcast came from the factory with a tire decal. 

I have seen, on at least one occasion, one of these decals on the black plastic portion of the fender, but i believe, at least as far as sandcasts are concerned, these decals were added by an owner, after the bike left the factory. 

The 2.71 printing of the parts book shows a tire decal to be used on the chrome fender beginning vin 13459.


greenjeans

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She's a runner....

Got to synch the carbs yet, but I think this one wants to go...  Fired with the 1st push of the button and will actually idle.
Going to synch the carbs tomorrow and take a spin around the block.

[IMG]

  
« Last Edit: March 04, 2012, 08:35:19 pm by greenjeans »


greenjeans

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I finally had a big block of time to work on 'ol sandie this weekend.    I put my wiring harness back on.  I replaced the majority of the connectors and re-wrapped it in some new non-adhesive loom tape.   Tested every wire for continuity.  1 less thing to worry about.

I got out the battery charger and did the electrolysis treatment on my wrinkle tank.  looks great in there, but I have a pin hole in a very odd place.  Bummer, but it should be an easy fix...eventually.   Since I really wanted to get it running, I was kinda bummed out.    Then, the motorcycle gods shined on me.  A buddy of mine just happened to be over at the house and mentioned that her dad had a bunch of old cycles and loved to show them off.  He has all girls, so he's out numbered and never really gets to show them off.   So, wanting to clear my head, I gave him a call and headed over.   I didn't know what to expect, but I was blown away.   He had a couple early HD knuckheads, a sweet panhead, shovelhead.   He also had a CB450 that he had bought brand new.   A late 60's Ducati that was just beautiful,  4 or 5 old BMWs and at least 5 old Honda dirt bikes.

After hanging out with him for an hour or so, I was just about to leave when I spotted an ruby red CB750 tank up in the rafters in the corner.    I asked about it and he didn't even remember how he got it - said it had been up there for at least 20 years.    I climbed up and got it down and it looked pretty solid.  A few love taps here and there, but solid.

I asked what he would take for it, not sure if he would even sell it or not.  He is one of those guys that doesn't like to part with things.    He gave it to me for $50 bucks and the promise of a ride on the sandcast when it is running.

So I raced back home, clean the tank out and got things ready to go.

New points plate - set the points and timing.   Re-checked the valve tappets.  Re-checked the cam chain.
All the wiring - checked and back in it's place.     Took the tappets off and put some oil in the top end.  Put a few drops of oil in the cylinders and popped some new plugs in there to go with the new coils I had purchased.     Put the new HM300s on there.   I have to say that it was the easy set of pipes I've ever put on.  Couldn't belive it.  I had all 4 on in about 20 minutes - with not a single curse word  
 I think I'm ready to fire this thing.

I put gas in the tank and then things started to go awry.  Gas was pissing out of everything.   I had re-used the original float needles and seats so I figured I could just change those out for the new ones I had but forgotten about.   When I took the bowls off, I noticed that all 4 of the over flow tubes in the bowls have micro tears in them...bummer !!!

I took the bowls off an extra set of carbs and swapped them in there.  Problem solved.

Went in and got the camera to document the first time this thing had fired since the late 80's

« Last Edit: April 17, 2012, 02:49:43 pm by greenjeans »