Stuck cylinder head tips?

[catdad]

Hi all.  Starting the fun process of restoring a nice little TMX100 and I'm having a hell of a time getting the cylinder head off so that I can see what shape the piston and cylinder are in.  Been spraying it w/ rust remover and penetrating oil (spray) for the last couple of days w/ good, but not too crazy, whacks w/ the rubber mallet, to no avail.  thing ain't moving at all.  (yes, all 4 head bolts are off )


Was thinking about maybe flipping the head upside down and soaking it in solvent or vinegar?  other tips that greater minds than mine might have?

thanks!

[OldSwartout]

If you mean just the cylinder head, they typically don't have an issue coming loose. If you have removed the four nuts and washers that hold it to the cylinder, it should come off relatively easily.  It's possible if you didn't get the washers off, they could have been mashed into the threads of the studs a bit, creating a bit of a lock.  You can try a screwdriver or other pry bar between the bottom head fin and the top of the cylinder, but be very careful that you get it deep in between and pry as little as possible against the outer edges of the fins or you may crack them. Otherwise, I'd screw the nuts back on the studs a few threads and hold the engine up by the head, and use them to tap against to drive the cylinder away from the head. It would probably take two people.

Another possibility is that if someone used a strong sealer instead of a head gasket, maybe it is in effect "glued" on. In that case heating to 450-500° F will reduce the grip and not hurt anything else.

[catdad]

If you mean just the cylinder head, they typically don't have an issue coming loose. If you have removed the four nuts and washers that hold it to the cylinder, it should come off relatively easily.  It's possible if you didn't get the washers off, they could have been mashed into the threads of the studs a bit, creating a bit of a lock.  You can try a screwdriver or other pry bar between the bottom head fin and the top of the cylinder, but be very careful that you get it deep in between and pry as little as possible against the outer edges of the fins or you may crack them. Otherwise, I'd screw the nuts back on the studs a few threads and hold the engine up by the head, and use them to tap against to drive the cylinder away from the head. It would probably take two people.

Another possibility is that if someone used a strong sealer instead of a head gasket, maybe it is in effect "glued" on. In that case heating to 450-500° F will reduce the grip and not hurt anything else.

thanks for the advice!  very much appreciated!

[hardy]

Hi Catdad,

Strange the head is stuck, but I have come across this before on a different two stroke. I found the studs has rusted and expanded into the head holes.

I would try some penitrene or CRC down the holes. Also check the studs are able to be wiggles slightly.

It me just be you need to get slightly more brutal with it, a soft hammer can help with the persuasion.

If all else fails, perhaps a plastic wedge aimed neatly between the head and barrel fins might help? Be careful not to bend anything!

Good luck, it will come loose!