I'm working on a 74 Sherpa T that I recently purchased. The bike was in storage for over 10 years and was reported to be "in running order" when it was put away. But after tearing in to the motor I found she is stuck solid. The broken kick start shaft probably should have been a clue

So now I need suggestions on how to get it apart to do a proper job of getting her back in order.

Any suggestions would be greatly appreciated.

By stuck, we assume piston + bore?

Yep, that seems to be the problem. I don't know if the bike siezed and then sat or if it is just corroded in place. I have the head off, exhaust and carb manifold. Lots of WD40 has been sprayed about, a limited amount of pounding and prying, but I don't want to damage anything.

I prefer something like Liquid Wrench to WD-40. And heat.

Where in the cylinder is the piston? Top? Bottom?

I believe one way to get it loose is a hydraulic press.

The most drastic thing I've heard of was one guy cutting the connecting rod.

I've always had more patience than that.

The piston looks like it is about 1/2" below TDC. So I am guessing it is in mid stroke.

I'll give the Liquid Wrench & heat a try. I have a lot of patience to go before I will be tempted to start cutting things.

And do you have access to a hydraulic press?

If you ever wanted one, now is a good time as you have an excuse...

If the piston is stuck it doesn't sound like you'll have it ready the Vintage Event down here in Oregon City nor Chehalis...

I would block up the ports that are exposed then fill the cylinder with diesel. Leave it for a couple of days

Hope this helps

Eddie

get a long breaker bar and socket on the flywheel bolt or magneto nut work it back and fourth, I like a block of wood placed on top of the piston, hit the block with a heavy hammer while putting pressure on the breaker bar, heat up the cylinder with a small torch or other suitable heat source, keep spraying wd-40, if it won't budge get an air hammer, the vibration from the air hammer will help to break loose the bond. I have broke the sleeve out or the cylinder trying to get a stuck piston out, sometimes they won't come out at all

Edited July 21, 200818 yr by MotoVintage

I have broke the sleeve out or the cylinder trying to get a stuck piston out, sometimes they won't come out at all

Some serious force that.... your not a dentist by any chance?

And a old mechanics safety note !!!! WD 40 is QUITE flammable even after the carrier has seemed to have evaporated .... Been there , done that !!!! Good luck !

Glenn

Edited July 21, 200818 yr by axulsuv

I can remember my Dad suspending a whole Norton 16H by the barrel when I was a kid. The idea was that the weight of the bike would keep the piston/cylinder sticking issue under load continuously. Soaking in penetrene and a hit on the piston crown every day with a wooden drift got it moving after about 4 weeks - lots of patience there.

The 16H had been parked beside a sand track through the dunes at the back of a beach for about 20 years (with the oil tank lid open)

get a long breaker bar and socket on the flywheel bolt or magneto nut work it back and fourth, I like a block of wood placed on top of the piston, hit the block with a heavy hammer while putting pressure on the breaker bar, heat up the cylinder with a small torch or other suitable heat source, keep spraying wd-40, if it won't budge get an air hammer, the vibration from the air hammer will help to break loose the bond. I have broke the sleeve out or the cylinder trying to get a stuck piston out, sometimes they won't come out at all

Lol - Reading down the post thinking, oh this guys got some helpfull advise. I get to the bottom and think perhaps I'll give this method a miss!!

I can remember my Dad suspending a whole Norton 16H by the barrel when I was a kid. The idea was that the weight of the bike would keep the piston/cylinder sticking issue under load continuously. Soaking in penetrene and a hit on the piston crown every day with a wooden drift got it moving after about 4 weeks - lots of patience there.

The 16H had been parked beside a sand track through the dunes at the back of a beach for about 20 years (with the oil tank lid open)

Sounds reasonable to save a Norton...

I had a look at one of my bull motors and remembered that you can remove the cylinder studs, this will give you a little more side to side movement and once you have the cylinder free of the case you can twist the cylinder a bit to help free the piston,

the cylinder that I broke the sleve out was a old husky that has an extra long sleve, I worked on it for a month trying to free it, I bought an old norton a few years back that the sleve was knocked out trying to free it, I have also had to do the rod cut to get one off on an old yamaha

and no I'm not a dentist, eeeww, but i do have a lot of experience working with old bikes

Thanks Moto,

Right now I am trying to use patience, Liquid Wrench and a few hammer taps. I have yet to resort to suspension, the torch, a bigger hammer, or the cut off tool, but they could be coming out soon. I thought about pulling the studs, that looks like it might help a little. Actually I think the hydraulic press might do the trick after the Liquid Wrench has a chance to do it's magic.