Pistons 2&3 stuck

!Seymore wrote: Question... 2 & 3 didn't get a bit skewed in the cyls' did they? ...and bind up for this reason? (just askin')

I mean... from what your OP reads, it sounds like you're in the middle of a rebuild and the motor has not yet been run, right? So I don't understand what's binding 2 & 3... When everything was on... can I presume you've had the head on(?)... did you spin the crank and everything moved ok? (just trying to understand where you are with all of this)

It has not run, the head has not been on. I think your right, the piston/pistons must be skewed.

gpz1170 wrote: if you are not putting tension on the cam chain when turning the crank, it will bind ( wad up ), locking up the motor.

I had the cam chain pulled straight up and zip tied out of the way.

PLUMMEN wrote:

!Seymore wrote: Question... 2 & 3 didn't get a bit skewed in the cyls' did they? ...and bind up for this reason? (just askin')

I mean... from what your OP reads, it sounds like you're in the middle of a rebuild and the motor has not yet been run, right? So I don't understand what's binding 2 & 3... When everything was on... can I presume you've had the head on(?)... did you spin the crank and everything moved ok? (just trying to understand where you are with all of this)

Maybe the rings folded over? :S :S

Can this happen?

You might move the barrels all the way up, then put some wood blocks between the sleeves and move the crank back and forth with a wrench. Sounds to me a oil ring may be jammed between the piston and cylinder. Do it gently and hopefully the pistons will drop out the bottom. Good luck.
Steve

swest wrote: You might move the barrels all the way up, then put some wood blocks between the sleeves and move the crank back and forth with a wrench. Sounds to me a oil ring may be jammed between the piston and cylinder. Do it gently and hopefully the pistons will drop out the bottom. Good luck.
Steve

Thanks Steve. The good news is that the liquid wrench was NOT sitting on top of the pistons this morning. I sprayed some more and am going to leave it alone while I take a family day. Hopefully this evening will have some positive results

kaw-a-holic wrote:

PLUMMEN wrote:

!Seymore wrote: Question... 2 & 3 didn't get a bit skewed in the cyls' did they? ...and bind up for this reason? (just askin')

I mean... from what your OP reads, it sounds like you're in the middle of a rebuild and the motor has not yet been run, right? So I don't understand what's binding 2 & 3... When everything was on... can I presume you've had the head on(?)... did you spin the crank and everything moved ok? (just trying to understand where you are with all of this)

Maybe the rings folded over? :S :S

Can this happen?

Like Plummen said, I think that you may have gotten an oil ring bent when putting the cylinders on. If just one ring is tweaked, sticking out of its groove, being between the piston and cylinder, it will be stuck.
Place a couple of pieces of wood under each side of the cylinder block, between the case and the block. With the rods mid stoke, Use another piece of wood and as a punch and a hammer to tap down on the pistons. Hopefully they will come loose and not be damaged. You may need another ring set for one piston. Someone on here may have a couple of oil rings or a set for one piston.

Thanks Motorhead, that's the plan, I just wanted the liquid wrench to get a chance to get in there and help a bit. Hopefully I will have some good news this evening.

swest wrote: You might move the barrels all the way up, then put some wood blocks between the sleeves and move the crank back and forth with a wrench. Sounds to me a oil ring may be jammed between the piston and cylinder. Do it gently and hopefully the pistons will drop out the bottom. Good luck.
Steve

I like the "move the crank" option, as opposed to the "tap on the piston". Might also try to move it more the position, opposite to what may have bent the ring, if you can guess/remember where 2 & 3 were when this problem started. May help to get it loose.

Also, might measure from the top of the cyl walls to the front and back of pistons 2 & 3, the cyls even with blocks beneath. Compare and see if either are askew... (troubleshooting?)

But enjoy your "family day" first... they do come first, in my household.

I don't see what good penetrating oil is going to do. That stuff is designed to loosen corrosion and the like from fasteners that have been in place for a long time. The stuck pistons don't apply if I'm understanding correctly. As the others have said there must be a folded ring or similar. Hope you don't tear up the cylinder wall or piston getting the cylinder back off.

Nessism wrote: I don't see what good penetrating oil is going to do. That stuff is designed to loosen corrosion and the like, from fasteners that have been in place for a long time. The stuck pistons don't apply if I'm understanding correctly. As the others have said there must be a folded ring or similar. Hope you don't tear up the cylinder wall or piston getting the cylinder back off.

I was hoping it might lube it just a little to help? It probably won't.

kaw-a-holic wrote:

swest wrote: You might move the barrels all the way up, then put some wood blocks between the sleeves and move the crank back and forth with a wrench. Sounds to me a oil ring may be jammed between the piston and cylinder. Do it gently and hopefully the pistons will drop out the bottom. Good luck.
Steve

Thanks Steve. The good news is that the liquid wrench was NOT sitting on top of the pistons this morning. I sprayed some more and am going to leave it alone while I take a family day. Hopefully this evening will have some positive results

Please don't pound on the piston. The best you can do is shock one bearing at a time in hopes of moving both pistons. That's a last resort. Aluminum doesn't take shock very well and may crack even if you don't see it. I said at the top of 2/3 piston stroke. That way they can only come down. Using pressure on the crank and a light tapping one to the other should coax the pistons down. Remember, you have rod bearings, wrist pins, pistons and skirts to think about. The last thing you want is any of them to come apart once it's back together.
Steve

Well I got them out. No major damage to the cylinder walls. Will have to rehone but the sight scratches I do have are in the skirt area so all is good. What I don't know is if any damage has been done to wrist pins or crank bearings. I really don't want to split the cases.