Topic: Sandcast #97 restoration

[slikwilli420]

Nice Repair Indeed

HONDA is sponsoring the 2019 AMA's Vintage Motorcycle Days at Mid-Ohio and will be looking for display bikes.........one or more may be asked to stay a while at the AMA museum near Columbus, Ohio.

Thats awesome! I go every year anyway. Would be neat to have my racer on display though Im not sure I could let it stay behind as it still has a specific job to do, race!

[SOHC4 Cafe Racer Fan]

+1 Great job on the fin repair.

[754]

What differences do you see between those 3 heads ?

[markb]

The only difference I can see is the missing spot faced holes on the E100 head. As I said earlier I missed that difference when I "carefully" looked them over before. Before I put them all back together I am going to look them over one more time to see if there is some other minor detail that I missed.

[MauiK3]

Wow, what nice work. What luck having that many low number engines.
Love the photos.

[markb]

Wow, what nice work. What luck having that many low number engines.

Thanks. There were a lot of hours of searching. The luck came when I found them. 

[markb]

If I would have done it right the first time I wouldn't have to do what I'm doing now. Oh well. It didn't take me long to decide that I had to do it. Just took me a while to get to it. 

The engine is out. This is just to document that it was, in fact, removed from the frame. Including removing everything that has to be removed first it took me about 4 ½ hours. It could have been 4 hours but I was taking it real slow so I wouldn’t ding anything.


And the wheels are off too. I need to have them redone with the correct spoke nipples. 

[Tews19]

Mark, have you ever scratched the frame and had to touch it up? Or do you simply PC the frame and all the frame parts?

[markb]

The frame is painted. So far I've managed to get this engine in and out with minimal scratches using padding on the frame. The main damage is where nuts and lock washers broke away some of the paint. They will be mostly covered again at reassembly. But yes I have scratched frames and had to do some touch up. Usually pretty unnoticeable. 

[Stev-o]

Nice work as usual...

[Don R]

 I've done a couple fin repairs like that, nice work, it looks really good. 

[bek1966]

New to this site.  What a fantastic project - thanks for sharing!

Brad

[MauiK3]

Markb
I’ve read this whole thread twice. It’s addictive to say the least.
I think you said at one point you were not going to ride it much, are you going to keep 97?
I’m sure you’d be a careful seller if you did sell it. It would be a shame for it to be abused.
What a magnificent restoration. It’s sad what came of many of the early 750’s: cheap choppers, botched customs, etc.
To my eyes, Honda has made several bikes that are works of visual art in stock form:
Early CB750
Early CBX
75 Gold Wing, not quite as attractive as the other two but still great.
What a tribute to your skill and perseverance.
Merry Christmas

[MauiK3]

I forgot the 400 four, pure art.

[markb]

I think you said at one point you were not going to ride it much, are you going to keep 97?

Thanks for the compliments. I need to get it running and hear it at least once but no I won't ride it much. As far as keeping it I'm not in any hurry to sell it but if someone came along with the right offer I would help him load it. 

[markb]

Before I swap the head I decided to split the cases to check out the kick starter. I used plenty of padding to protect from damaging the cases.


Something was causing it to lock up. I confirmed that it was assembled correctly and it worked with the cases apart. I took the assembly apart and comparing the parts to others I have everything looked fine. The only thing I could think of was I had not put any grease on the shaft where it goes through the clutch cover.


I put it back together with different parts and installed a new pawl spring. The only other thing I did was polish the ends of the shaft and lubricated them before reassembling. Then I put it all back together and installed the clutch cover and now it works fine. Could it have been that the shaft was binding in the clutch cover because it was dry?  I could have saved myself a lot of work but I had to be sure.

[markb]

Ok, I might have a change of plans. My next project was to swap the head and cylinder and put in the originals. I was going to put in the o-rings on the bottom of the cylinder and something didn’t look right. So I dug out the cylinder from E748 to compare. The bottom of the sleeves are different. E748 is on the left and E100 is on the right. Besides fixing the fin I had to have the cylinder resleeved and rebored because it had been bored to 1mm over. I’ve got to start paying closer attention.


Externally the E100 cylinder looks the same as the cylinder that’s on E100. So I’m thinking do I want to be correct or original? If this were the only original part on the engine that would be one thing. Clutch and transmission are not original. If you’ve seen earlier posts you know why. The other thing is I tried removing one of the rubber inserts between the fins. The nibs broke off. I think I have just enough to do the head but definitely not another cylinder. Maybe I could find some more. Maybe they would only cost $100. Bottom line is I’m thinking of only swapping the head. I have to do that to be correct.

[MauiK3]

Tough decision but if you eventually want to sell it, the closer to correct and original it is I think the higher the value.
Might be hard to get both all at once.

[markb]

I guess I agree with that. If I had enough of the rubber inserts to install in the original cylinder I probably would go that way. Before I do anything I am going to try to find some, again. Past experience was they are pretty rare, at least to get the right color.

[MauiK3]

If you can't find the right rubber bumpers (vibration attenuators?) you could document the change and put a newer set in so it's mechanically correct and sound, that would seem to satisfy the need for the bumpers and the need for historical correctness.
Number 97 now has a life of its own and should be somewhere where it will be preserved. Ridden as well but preserved.
If I were ever to rescue another it would be a K0 and maybe a sandcast if possible. As a design they were not perfect but as we all know, that's not the point, they were the first and as such they are awesome. As time goes by they will get harder and harder to bring back properly.
I'm getting excessively reverent here :-))
I'm not a habitual restorer like so many here but I really respect the process, I've just got too may things going on to do it very much. As a habitual DIY I seem to always get into stuff, like I'm about to start my kitchen over (again).
#97 is wonderful and I'd buy it if I could afford it. Keep up the stellar work.

[markb]

So I decided to go with the original jugs. I figured I would keep looking until I found the inserts. Here I am ready to put it back together.

Things are going pretty good and I took a little break and checked the SOOC website and one of the guys had a link for an eBay sale that had the inserts. Sweet. Now I feel good about my decision. So I got the jugs and head on and I’m thinking could things go any better. Well the answer to that was no. I torqued down the 16 head nuts and then when torqueing the 6mm screws under the pucks, one of them stripped out.   

That’s where I quit for the day yesterday so I could think about what to do. I decided to heli-coil it. I thought about trying to do it in place but decided the best is to pull the cylinder off and do it right. There isn’t a lot of room between the hole and the flange on the cylinder sleeve so it seems like the tap drill and tap may go into the flange. I think the sleeve is soft enough for that. My only other decision now is while I’m at it should I do all four?

[kmb69]

.....
My only other decision now is while I’m at it should I do all four?

Yes, heli-coil all 4.

Not sure what you were using but, you need to be real careful torqueing 6mm screws. I prefer to use a 1/4" beam type torque wrench for small screws versus a "clicker". Most "clickers" say specifically their quoted accuracy is "when they left the factory" if you get my drift.

[markb]

Seems like the thing to do doesn’t it. I do have the clicker type but I check it quite often. For 6mm bolts I try to stay around 80 lbs. in.

[MCRider]

Its always been my opinion that the 4 6mm bolts UNDER THE PUCKS, are there for convenience. To draw the head down in a uniform way before getting on the head nuts. The head nuts do the heavy lifting. 4 6mm bolts in soft aluminum can't be expected to do anything else of any value. In fact its my opinion that after torquing the nuts those bolts are immaterial and should only be tight enough to keep them from backing out and rattle around. Heck I think you could leave them out entirely, truth be told.

But its not my bike.   

[markb]

Heck I think you could leave them out entirely, truth be told.

I've thought about that too.  It does seem like they don't do much. However, I am going to put them in.

I been told that when tightening you need to do the nuts first then the screws otherwise the screws will be loose. When loosening do the screws first then the nuts otherwise the screws will get tighter. Seems logical to me.