Topic: Sandcast #97 restoration

[Magpie]

MCRider, the very early covers were quite a bit lighter and thinner, at least on my early motor. The first picture is a dyno cover of s/c 260 and the lower one of a K0 motor. Notice how thin the "lip" is on the early one. I think that's what Mark is referring to. Cliff.

[MCRider]

Velly interestink.

[markb]

I think that's what Mark is referring to. Cliff.

That's exactly right Cliff.  Thanks for the post.  They're one of the really rare items, only used up to VIN 2134.  Mine (and Cliff's) is even rarer because it also has the smooth, not dimpled, background on the Honda logo.  That feature only went up to #342.  That is why I really needed to save this piece. 

Cliff, you wouldn't want to sell me yours would you? 

[Roach Carver]

 I am so glad you bought it and I had the sense not to. You are the man for this job and it is obvious. I would not have the patience for such a tedious build/ restore or the pocket book for it either.

[Magpie]

Sorry Mark!    Cliff.

[HondaMan]

Good luck with your project.  Are you doing a thread on it?  I'd love to follow it.

You may have nudged me into it: I was going to do things like stainless bolts on all the not-so-pretty ones, but there sure is the allure of saving the OEM ones if I can figure out how in the world you polish those up so nice? I'd really rather keep mine as (externally) OEM as I can. The rear fender and taillight bracket may have to give up, due to previous experiments that have left too many holes in both, but I have an identical K2 rear fender to help me feel better about that (and it has a dealer sticker on it that says, "Paris Cycle Sales", of all the luck!). I even got an early K2 grab bar back (thanks, Gammaflat!), which was really a late K1 with different turn signal mounts added by Honda. That was a hard-find part for mine, as mine fell victim to an accident in 1972 and was finally removed in 1988, from jagged edges where my hand went(!).

Somehow, I don't think my quality will match this. Your techniques rock!

[markb]

(and it has a dealer sticker on it that says, "Paris Cycle Sales", of all the luck

That is pretty cool!

Somehow, I don't think my quality will match this. Your techniques rock!

Thanks again for the compliments.  It just take time.  Sometimes I wonder if it's worth it but when I'm all done I'm sure I'll think so.  So did you start a thread?

[markb]

I know I’m jumping around a bit but towards my goal of getting all of my polished aluminum done I tackled the front forks so I could get the lowers off.  They actually came apart easier than I expected and look pretty clean inside.  The seals look really good so I think they must have just been replaced before it was parked.  They will get replaced of course.


There was a sticker on one of the lowers.  It’s a little hard to make it out but at the top it says Oklahoma and the bottom shows that it was last inspected (and presumably ridden) in 1979.


I took the tubes out of the lowers so I can clean everything inside easier.  Notice the special screw and washer.  It’s a good idea to replace the washer to prevent oil leaking out the bottom.  Guess how I know that?  They are not shown in the Honda parts manual but they are both available from Yamiya.  The washer is part number F146 and the screw is number F147.


There was what looked like wear on one of the pistons.  They are discontinued but I measured it and it was 1.552” diameter (above the serviceable limit of 1.551”) and it was round and straight within spec too so I’m using it.  The springs were well in spec too so I’m going to use them too.


All these little rings are also discontinued so I veeery carefully removed them.  They are all very similar so I measured them and recorded the sizes in my parts manual so I wouldn’t mix them up at reassembly.

[markb]

So now what to do with the tubes?  The top halves of the tubes are pretty rough.  The bottoms were OK and no one would see how bad they are but I would know.  I considered having them built up and reground but decided against it.


I also considered tubes from Yamiya and Forks by Frank but fortunately I was able to score on two Honda NOS tubes.  I had to buy them from two different sellers but I can’t believe I found them. 


I was a little concerned that they might have some surface rust on them but they were clean on the outside.  What little there was on the inside cleaned up nice when I stuffed an oily rag through them.


I inspected them carefully and they match the originals exactly.


I decide to put them together before I misplace any of the parts.  Here they are all assembled.  I oiled them up real good on the inside and outside and wrapped them up to put away until I need them.  It feels good to actually get something put back together.

[hoodellyhoo]

It feels good to actually get something put back together.

I bet!

Glad to see the project is moving along again. Your attention to detail is amazing.

[markb]

I got another little project done.  This is probably the ultimate in anal but I’m glad I did it.  Remember my rear brake panel with the notch broken out?


I wanted to rescue it because it is different from later sandcasts.  It’s the only one I’ve seen like it.  The one on the left is from #97.  The one on the right is from #1553.  Notice the 4 round areas on the ribs near the center hole of the later one.  There seems to be some subtle differences on the outside too but nothing distinct.


I had my welder use some of my homemade welding welds to fill it in hoping the color would match.


Then I made up a fixture so I could put it on the mill and machine the OD and backside.  This is after machining.  I was tempted to use a burr and try to remove some of the extra weld to make it look less like it was repaired.  I still might.


And here’s the outside.  I did it all with a file and sandpaper.  Very tedious.  Still a lot of polishing to do on the rest of it but I think it turned out great.  You have to look really close to see it.  Me and you guys are the only ones who will know that it is a special, early, rare sandcast part.  But that’s part of the satisfaction of it. 

[ohiocaferacer]

NICE!!

[DV2000NJ]

The attention to detail on this is simply mind blowing.  I love it!

[UK Pete]

Mark that repair is amazing, i have two repairs to do to my rear hub which will involve welding i do hope i can find someone here in the UK that can do the welding and machineing for me, and get results like yours
Pete

[Garystratos201]

Nice work !!!.........Gary

[HondaMan]

(and it has a dealer sticker on it that says, "Paris Cycle Sales", of all the luck

That is pretty cool!

Somehow, I don't think my quality will match this. Your techniques rock!

Thanks again for the compliments.  It just take time.  Sometimes I wonder if it's worth it but when I'm all done I'm sure I'll think so.  So did you start a thread?

As soon as I get my 750 onto the patio! Can't wait...

I just stumbled upon a "tumbler for brass", which seems to be for small parts. Do you know if this is a good gadget to use to shin-ey up the bolts and washers? I think it is supposed to be used for bullet cases, but small parts are small parts...?

[markb]

I've never tried something like that but I don't know why that wouldn't work.  I've never had much luck cleaning up zinc plated parts to my liking.  I usually just "bite the bullet"  and get them replated.  If you try it let us know how it works out.

[markb]

I’ve been procrastinating what to do with my rear driven flange.  It has deep grooves worn in it from the chain guard.


In the worst areas they may be up to 0.5mm (.020”) deep or more.  Hard to believe that a plastic chain guard could cause so much damage.  I considered using the one from #1553 but it wasn’t much better.  And since this is a common problem it’s not likely I’ll find an early one without gouges so I decided to try to save it.


I was tempted to put it on the lathe but in the end I did it all with files and sandpaper.  I took a couple of hours but it turned out great!  I still have plenty of work to do but the hard part is done.


While I was working on it I noticed something interesting.  There are three center punch marks on the hub.  Apparently this is an indication that a recall was done on the cush rubbers and drive chain.

[Greggo]

The hub looks great Mark!  I hope you're not logging your hours spent on this one

[markb]

I started to and then I decided that I really didn't want to know. 

[Greggo]

I started to and then I decided that I really didn't want to know. 

It would be fun to log them, then add it up at seventy five bucks an hour...if anybody ever tries to buy the bike from you, just give them the total and tell 'em that's the price

[MCRider]

I started to and then I decided that I really didn't want to know. 

It would be fun to log them, then add it up at seventy five bucks an hour...if anybody ever tries to buy the bike from you, just give them the total and tell 'em that's the price

Even $10hr would put many restos out of reach.

[HondaMan]

I’ve been procrastinating what to do with my rear driven flange.  It has deep grooves worn in it from the chain guard.


In the worst areas they may be up to 0.5mm (.020”) deep or more.  Hard to believe that a plastic chain guard could cause so much damage.  I considered using the one from #1553 but it wasn’t much better.  And since this is a common problem it’s not likely I’ll find an early one without gouges so I decided to try to save it.


I was tempted to put it on the lathe but in the end I did it all with files and sandpaper.  I took a couple of hours but it turned out great!  I still have plenty of work to do but the hard part is done.


While I was working on it I noticed something interesting.  There are three center punch marks on the hub.  Apparently this is an indication that a recall was done on the cush rubbers and drive chain.

You're right about the 3 marks: IIRC, our shop only used one of those automatic centerpunches, nothing as deep as those are.

[sandcastcb750]

The differences in these parts is probably because Honda shopped out to several places and small batches of parts at that. According to Bob Hanson when I talked to him years ago at Mid Ohio, he said Honda didn't think they were going to sell very many of these CB750s in the beginning.

[markb]

On to the oil filter cover.  There is a lot of road blast on it.  And there are pits and imperfections all over it which I’ve learned are typical on the early smooth covers.  My plan is to remove enough of the blast to make it look about the same all over.


I carefully chucked it in the lathe and went to work with sandpaper.  I think it turned out pretty good.


There are still plenty of imperfections.  It’s hard to resist removing them.  Next a brushed polish finish and then clear coat.