Honda CB750 Sandcast

Restoration of Sandcast #97

markb · 814 · 285420

markb

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Anyone familiar with a product called AlumiWeld for repairing aluminum?  Here's a link:
http://www.alumiweld.com/index.html
I could try it on my "test" 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?)


donzie

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Mark I have used this stuff several times on many repairs. Many names but all about the same stuff. It works & flows just as described but this is not welding it is more of a solder. Welding combines by melting the parent metal & the welding rod together this stuf just flows on top of the parent metal. If your base is super clean it should flow & fill any pits & can then be machined, sanded or filed


markb

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Mark I have used this stuff several times on many repairs. Many names but all about the same stuff. It works & flows just as described but this is not welding it is more of a solder. Welding combines by melting the parent metal & the welding rod together this stuf just flows on top of the parent metal. If your base is super clean it should flow & fill any pits & can then be machined, sanded or filed
How is it for a color match?

I got a suggestion from the SOHC4 site to use material from an old cover to make a welding rod.  That way the color will match.  Sounds crazy but plausible.  Anyone have experience with this?
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?)


kp

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Mark I have used this stuff several times on many repairs. Many names but all about the same stuff. It works & flows just as described but this is not welding it is more of a solder. Welding combines by melting the parent metal & the welding rod together this stuf just flows on top of the parent metal. If your base is super clean it should flow & fill any pits & can then be machined, sanded or filed
How is it for a color match?

I got a suggestion from the SOHC4 site to use material from an old cover to make a welding rod.  That way the color will match.  Sounds crazy but plausible.  Anyone have experience with this?

Whilst I've never seen it done would sound a plan if it worked. I'm not sure if cover materials changed as Honda moved into high production so this would be the only question. If you can get an early damaged cover (not a thin lip) would be worth a shot. 
Yabba Dabba KP


Riccardo

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Mark, I think that the point to weld is much little one and is in the inferior part of the cover.
After the polishing and the paint job it will be impossible to see it.
Certainly, if you search the point of the weld, sooner or later, you find it.
Riccardo
Your Italian friend.
737/940 Restored
1081/1362 Preserved
1256/665 Restored - ex Owner: Chris R.
10253/10315 (K0) Next project
1969 - Kawasaki H1 Mach III low ign cover - Restored
1969 - Kawasaki H1 Mach III high ign cover - Restored
1971 - Kawasaki H1A - Restored
1973 - Kawasaki H1D - Preserved
1973 - Kawasaki Z1 Blackhead - Restored
1971 - Norton Commando SS - Preserved
1978 - Honda CBX - Unmolested Museum Quality
1988 - Honda CB 400SS - Unmolested
1997 - BMW R80 GS Basic - blue frame - Museum Quality
2007 - BMW HP2 Megamoto - blue frame - New


markb

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Whilst I've never seen it done would sound a plan if it worked. I'm not sure if cover materials changed as Honda moved into high production so this would be the only question. If you can get an early damaged cover (not a thin lip) would be worth a shot.  
Any one have an unrepairable sandcast cover to get rid of?  It wouldn't have to be an alternator cover.  I have a non-sandcast rear sprocket cover I can play with but I'm not sure of the age.  Maybe the material is the same but I'd feel better having "old" material.
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?)


markb

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I'm meeting my welder tonight.  I remembered I have a scrap valve cover that came off my K0 (sorry, early diecast).  It had a build date of 11/69 so the material is probably as close as I can find to the sandcast alternator cover.  He's going to do some test welding to see if he can get a close color match.  I'll post the results.
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?)


markb

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I didn’t get much done last weekend; I picked up a basket case sandcast engine.  Because of all the water in the crankcase of #97 the transmission and clutch are pretty rough so when I had a chance to grab a parts engine I figured I better take it.  Following the rule of not leaving anything behind, I asked the seller if he had any other parts.  He said he had a set of carbs.  I asked him how much and he just threw it in with the engine.  Which was good because the cases have some repairable issues but I figured with the carbs I’d come out OK.  Here are a couple pics of the carbs.



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?)


kmb69

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Nice 28 carb score Mark!

What's needing repair on the cases? You mind sharing the engine number?

Keith


Riccardo

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Mark, i think that you can do a good job on those carbs.
Long choke lever? Or short lever they have?
Riccardo
Your Italian friend.
737/940 Restored
1081/1362 Preserved
1256/665 Restored - ex Owner: Chris R.
10253/10315 (K0) Next project
1969 - Kawasaki H1 Mach III low ign cover - Restored
1969 - Kawasaki H1 Mach III high ign cover - Restored
1971 - Kawasaki H1A - Restored
1973 - Kawasaki H1D - Preserved
1973 - Kawasaki Z1 Blackhead - Restored
1971 - Norton Commando SS - Preserved
1978 - Honda CBX - Unmolested Museum Quality
1988 - Honda CB 400SS - Unmolested
1997 - BMW R80 GS Basic - blue frame - Museum Quality
2007 - BMW HP2 Megamoto - blue frame - New


kp

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Mark, i think that you can do a good job on those carbs.
Long choke lever? Or short lever they have?
Short  8) How did I know that  ???
Yabba Dabba KP


markb

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I was wondering if anyone would notice the 28's.  ;)

The set is missing two floats and bowls but yes, still a nice score.  So now I have a set for 97 & 1553.  I've had a little bad luck on this project (not complaining) so it's nice to have a little good luck.  It is the short lever, by the way.  kp, how did you know that??  My carbs for 97 has the long lever and also has the horizontal vents.  Is that how you tell?

The engine is 1490.  It is missing the alternator cover (was hoping to get one of those) but it looks like everything else is there.  Hard to tell when it’s all apart.  There is a broken stud and some damage to the cylinder mating surface on the top case from “aggressive” disassembly.  There is also a crack on the rear of the bottom case.  The outside bearing on the final drive shaft was missing its balls so it looks like when the bearing went out the drive shaft pulled back and the final driven gear hit the case on the inside and cracked it on the outside.  It’s been sitting for a while since that happened.  The crack is in the middle of the flat surface on the rear of the case and my welder says no problem fixing it.  It probably won’t even show after blasting and painting.  Not sure what I’m going to do with the cases yet.  I had a guy interested in them before I picked up the engine but he won’t get back to me now.  I may end up using the transmission for E100.  I’d like to try to use as many of the original parts as I can but most of it is still rusted together after much soaking and cursing.  At least I have options.
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?)


kp

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Mark, a PM coming.
Well there were 3 ways to tell on this occasion
#1. The vent tubes are 90 degree. The straight type are always the longer choke lever
#2. At the edge of the picture which shows the choke lever, you can just make out the beginnings of the distortion which makes the flat section where the choke writing is.
#3. (and this is the clincher) Given #1 & #2 above, I guessed  ;) KP
Yabba Dabba KP


kp

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Need a Long Choke Lever.
Fairly easy to produce a long choke lever.
Step 1. Take 2 choke levers and mark/scribe both at the midway point between the flat (where choke is written) and the 90 degree bend at the other end. Choke levers are common to a variety of Honda carbs.
Step 2. Cut one lever at this point. Try and get a nice cut.
Step 3. Take lever #2 and add the extra length from the scribed mark down the lever and make a new mark.
Step 4. Cut the second lever at this point. You now have 2 sections of choke lever that will be TIG welded together to make a long choke lever.
Step 5. Find a welder who has a TIG machine. Don't even try a MIG
Step 6. After your welder has done a super job of welding then find a machinist to clean up the job
Step 7. Zinc plate .................. and Uncle Bobby truly is your Uncle Bobby  ;D
Yabba Dabba KP


Riccardo

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KP,

sincerely, after 2 years of sandcast forum observation, i admit that i dont know exactly the differences from early to late carbs bodyes.

Yes i know the long or the short choke lever, the 28 top carb with 6 mm adjiuster screws, skinny cables, etc,  but i remain with some doubts.

Because i read that you know well the carbs, is possible make a list of differences, to do a point firm about the carbs (from early to late model)?

Thanks
Riccardo
Your Italian friend.
737/940 Restored
1081/1362 Preserved
1256/665 Restored - ex Owner: Chris R.
10253/10315 (K0) Next project
1969 - Kawasaki H1 Mach III low ign cover - Restored
1969 - Kawasaki H1 Mach III high ign cover - Restored
1971 - Kawasaki H1A - Restored
1973 - Kawasaki H1D - Preserved
1973 - Kawasaki Z1 Blackhead - Restored
1971 - Norton Commando SS - Preserved
1978 - Honda CBX - Unmolested Museum Quality
1988 - Honda CB 400SS - Unmolested
1997 - BMW R80 GS Basic - blue frame - Museum Quality
2007 - BMW HP2 Megamoto - blue frame - New