I had a local machine shop drill and tap this plate of steel to help me pull the cylinders on my GT500 project. We are really putting the beans to it and the cylinder isn't budging at all.
My goal is to pull one cylinder at a time. Does anyone have any advice? We're going to let it sit overnight with a fair amount of pressure to see if that gets us anywhere.
Does that puller push off of the piston? If so, I would be fearful that the piston and/or the connecting rod would get damaged. I have never used a cylinder puller before, but what I usually do is get a small block of wood and a hammer to carefully tap the cylinder off. Are the pistons stuck in the cylinders?
crazyeights wrote:Are the pistons stuck in the cylinders?
The pistons are soundly seized into the cylinders. I've been soaking them in penetrating oil for quite some time in preparation for this adventure.
crazyeights wrote:Does that puller push off of the piston? If so, I would be fearful that the piston and/or the connecting rod would get damaged.
It does push on the top of the piston. They're so seized that I'm not concerned about damaging the tops since I'll be boring out the cylinders and replacing with new pistons.
Can anyone tell me if the issue might be with the cylinder studs being seized in their openings as well?
It's a bit unorthodox....I can see the piston shattering before the jug moves tbh. Pushing down onto the studs would be more likely to succeed I think. I have had a couple of very stuck jugs in the past, but a lump of wood in the exhaust port, and a big hammer has eventually done the job, though they were only ever stuck on the studs....not the pistons.
Is there rust in the bores?. I had a 750 that was stuck just from sitting 25 years. After weeks of every penetrating fluid known to man and a very expanded vocabulary, I got pissed off, grabbed a block of oak, got out my BFH an wailed the top of all 3 pistons. She freed right up like there was never anything wrong with it. There was no rust in mine though. If yours is seized from rust, not sure what I would do. Maybe intentionally breaking the tops of the piston out so it is no longer attached to the rod, a different plate that pushes on the studs might not be needed once the piston is free from the rod. The bike looks sadly neglected. I hate to see that.
I would be vert afraid of damaging / collapsing the upper rod hole going at it the way you are. Time to regroup!
I was born with nothing and still have most of it left.
I guess what I'm wondering is if the studs that proceed up from the block, through the cylinder jug, are a tight fit and hence the jug is hanging up on those as well?
We tried some oak and BFH prior to this. There is some rust inside the bore.
Lastly, and I'm embarrassed to ask, but these are two separate jugs, correct? I mean, I don't need to pull both cylinders at the same time, right? Everything I see points to the idea that there's a left and right cylinder and they're independent units. Just making 100% certain here...
They are separate. Look at it this way. The piston is aluminum. It can't rust. The only thing that can rust is the rings. I would say that it is definitely the studs that are frozen. Make another plate that pushes on the studs. Lots of penetrating oil and lots of heat in the area of the studs. That plus plenty of patience.
Last edited by Coyote on Wed Aug 26, 2015 3:36 pm, edited 1 time in total.
I was born with nothing and still have most of it left.
If you must bear on the piston, place a thick piece of old hardwood on top of the piston. I used a really BFH (4lb plus and 200 big blows) to drive out a weld-seized GT550 piston out recently and the piston crown came out with zero marks on it
I then rebuilt everything from crank on up but as you will be, I was grateful that I could get the blessed thing apart!
Mike
Coyote wrote:The piston is aluminum. It can't rust. The only thing that can rust is the rings.
I was thinking that the fins and such are aluminum but the actual bore is a steel sleeve inside the aluminum.
One of the studs actually came out when we were removing the heads. It didn't break or anything, just unthreaded like a long bolt. I hope that's not a bad thing. Stay tuned. I'm determined to get this apart. It's just metal, right?
Have you split the cases and took a look at the crankshaft yet? (I believe it can be done with the cylinders in place. Unorthodox, but possible).
If the top half is as seized up as what you are dealing with, I wonder if the crankshaft may also be so far gone to make it unviable as candidate for rebuild.
These types of pullers tend to rely on a good sound tap on the bolt with a hammer once everything's tightened up......you can't really do that while the bolt rests on the piston. Maybe some sort of plate on top the piston could help.
ConnerVT wrote:Have you split the cases and took a look at the crankshaft yet? (I believe it can be done with the cylinders in place. Unorthodox, but possible).
We haven't split the case yet. Our plan is to replace the main bearings anyway. If the crank is shot and/or the transmission is seized, I'm afraid we might have to let this one go. We'll keep on the hunt until we meet that threshold.
