Rupp Chopper Restore

MSPTREX

Active Member
#1
Picked this thing up about a year and half ago. Decided it is time to bring it back to mostly original. I have already got the ball rolling by hitting up Manchester1 to get on her seat waiting list, sent turbines off to cambo61 to be burnished, and got bike all torn down to get blasted and ready for powercoat.

The bike came with a 3hp Briggs when I purchased it but I was lucky enough to find a gentleman with an original but locked up side tank h25 tecumseh that would of came on the bike originally. With that being said lets hear some tricks for breaking loose a stuck piston in the bore!

Things I need help finding:
- Wheel Hardware for the Turbines
- Original Clutch Cover (already have a repop just in case)
- Old School 6" Goodyear knobbies
- Original style bolt-on kickstand

Any tips for the restore would be great! Thanks
 

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MSPTREX

Active Member
#2
cambo61 recieved my wheels so here is some before pictures. Ill post pictures of the after when he is finished with them.

Ive got quite a few things ordered like grips, foot peg covers, twist throttle, gray throttle cable, and hardware. Will post more pics soon.
 

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#3
This is going to be a great build. Lucky you found that side tank. Lol. I had a Yamaha 80 that the piston was stuck and I kept hitting it with PB blaster for a few days. It worked.!!!!
 
#7
Exactly what I have been doing haha switching back and forth from ATF to PB Blaster. It will break loose eventually.
Try this and you will be amazed. Let it do its thing for a day or 2 and it will break free. I buy it direct from the manufacturer by the case. I don't own any PB anything... And WD-40 is for changing tires.

Welcome to GIBBS Brand Lubricant


The folks on the H.A.M.B. use it religiously. It will stop oxidation of Magnesium parts. If you have been around anything magnesium it looks like crap in short order. But the Gibbs will seal the surface and it will look nice for years.


It will seal bare metal and is paint friendly too.


https://www.jalopyjournal.com/forum/threads/about-gibbs-brand-penetrating-oil.137392/



An old thread I started.

https://www.oldminibikes.com/forum/shop-tools/132760-gibbs-penetrent.html?highlight=gibbs
 
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MSPTREX

Active Member
#9
Few updates. Turbines are back from being burnished by cambo61 and of course they look amazing. Sam has burnished quite a few wheels for me now and never disappoints. He even made the sprocket and bearing spacers look new again! Unfortunately the chrome wheels halves are pretty toast. Pitted severly on 1 and other 2 are not the best, I will add a few pics of them.

So my options are to find nicer wheel halves, have these filled in with filler and painted chrome, or find a place to rechrome them.

I would like to either find a different set in good shape or have them rechromed. With that being said anyone have 3 nice wheel halves or know of a good chrome restoration shop?
 

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MSPTREX

Active Member
#10
Also was able to get the H25 completely tore down. Took about 20 mins to remove the flywheel. With a 3 jaw puller, a torch, and a rubber mallet it finally "popped" off after taking my time not to break it.

After that I removed the rod cap and was able to get the crank pulled out as well. After soaking the top and bottom of piston for weeks with various things I am tired of waiting so with a large diameter pipe and a hammer I knocked piston out of the bore. But not before poking a hole in top of the piston. I really had to wack pipe to get the piston out. Was really seized in there.

Now its all disassembled the bore is really bad. Possibly beyond repair. Sometime soon I am going to take block to machine shop to see if a .020 piston will even take all the bad spots out to be good enough to run. If not I will be on the hunt for a donar block.
 

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MSPTREX

Active Member
#14
Project is moving along slowly. Since the chrome wheel halfs where so rough I had no choice but to either get different ones or have these rechromed. I decided to send them off to Tennessee to be welded on to fill in the pits then smoothed out before new chrome. I will attach a few pics of before I sent them off.

Unfortunately my H25 block is too far gone and even a +.030 piston wont be enough to get a good bore. I do have another Tecumseh here missing its identification tag, I need to pull head and measure the bore to find out what it is. If it is an H25 I will tear it down and use block as a donar.

The frame and forks have been sand blasted and to my surprise there is no cracks or holes anywhere on the frame. Super happy about that. Im hoping in the next week there will be some orange powder on both.
 

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MSPTREX

Active Member
#15
Update on whats going on. Couple weeks back I sent my chrome wheel halfs to advanced plating in Tennessee to get restored and chromed. Just my luck the facility caught on fire this last weekend. Luckily my wheel halfs are not compromised but could be up to a month before I get them back. Then I have to find some where else to send them to be restored.

Not much progress on the frame as my powder coat guy came down with pneumonia. He has the bars coated and the frame blasted. He is feeling better but still low on strength. He is hoping to finish it soon.

I was able to score another h25 block since the original ones bore is trashed. Once I scored it I went ahead and ordered $200+ in NOS tecumseh parts to make it like new again. Cant wait to start on it!

I did ended scoring some 4.10/3.50/6 Goodyear tires in amazing shape to use on the bike. That is originally what would of came on the bike. Ill get them cleaned up and get some pics.

And the lovely manchester1 finished my seat and like always it looks amazing. Once it arrives I will get some pics and post them up. Slowly but surely the bike will get finished.
 

MSPTREX

Active Member
#19
Recieved my seat from the talented manchester1. And as always she killed it. I can't wait to see what it looks like on the bike. I can always count on her for amazing quality and fitment. This is my 4th seat I've had her do and can't wait for the next 4 haha

I snapped a couple pictures of the Goodyear tires I scored for the restore. These where actually on a set of Mickey Thompson wheels I found. Havent found a Mickey Bike to go with wheels so they will used on the chopper. They even have the original good year tubes in them.

Still waiting to hear on my wheel halves. In the mean time I purchased a parts bike that hopefully has nicer wheel halves then I was having to work with. Just have to wait for it to show up in the mail.

I am still in search of the correct kickstand for this bike if anyone has one. Also looking for an original clutch cover, I have an repop fiberglass one to use but rather have an original.
 

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#20
Thank you for the compliment Kyle. Your making good progress.:thumbsup: You need to find somebody that has one of those bikes with a kickstand so you could bend one up. Maybe find out if that frame is the same as any other Rupps.
 
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