Stuck cylinder

[carhartted]

This is my first post, this is a great forum. I have been lurking for quite a while. Here is my problem.

I have been working on a stihl 031 and was trying to get the jug off and replace the rings. But as I was removing the jug from the piston it stopped, now the jug is stuck on the piston and I can neither pull the piston out or push it bach into the cyliner.

When I was trying to get it off the jug got twisted slightly on the piston and now the jug won't turn back and to mate with the bolt holes on the saw body.

I'm stuck, literally, and don't know what to do.Do you guys have any suggestions.

Thanks

 

[Tony Snyder]

That is bad news. If the ring is stuck in the intake or exhaust you might get the ring back out of the way with some sort of tool. If it is stuck on a transfer, you probably got a parts saw on you hands.

Lets see what the experts here say.

Of course you should never let the piston rotate, in case you haven't guessed.

 

[stihltech]

031

Was the unit turning over OK before disassembly?

If it was, one of the rings is caught in the port or the piston is cocked in the bore enough to wedge.
Look in the exhaust and intake ports to see if the end of the ring is visible. You may be able to carefully push the end of the ring back into the piston and free it.
If not, carefully turn the cylinder while trying to slide it up and down. This may free the ring from a transfer port. Aslight tap with a small cushioned hammer may also pop it loose. No BFHs!
I have had this happen in the past. I have always gotten them loose, but patience will be a virtue while doing it.

Good luck. Let us know how you make out.

 

[timberwolf]

This would not likely help if the ring is caught, but the combination of heat on the jug, and cold on the piston might allow enough clearance to break it free.

I think I would try the heating/cooling before the last ditch force method.

Timberwolf

 

[carhartted]

The saw turned over fime before I tried to fix it.

I am able to move the piston about 1.5 inches up into the jug before it binds agian.

Thanks for all the help

 

[Tony Snyder]

Why don't you take it to your stihl dealer and let him break it.

Na just kidding. But, you are in a rough spot and may not get that off with ruining the upper end. Than get some parts from dozerdan and go a gain.

I've got a couple of non-runner 031s but I don't know what shape they are in, and really don't have time right now to disassemble.I'm behind on repairs.

 

[Fish]

Look in the intake and exhaust ports, you should see a
piece of ring sticking out.

 

[Crofter]

The fact that you can move it up and down 1 1/2 inches makes me think that the ring gap indexing pin in the piston has rotated out under the ring, and is bulging out into a transfer port. If you force things you will do damage. It is easy to distort the connecting rod. Some of the fellows who do porting on 2 strokes open a window on the outside for access. That might be a possibility but is a very long shot. Like doing brain surgery on a billygoat. You are caught between a rock and a hard place I think. Good luck.

Frank

 

[stihltech]

pin

The fact that it turned over OK before you started disassembly and that you turned the cylinder tells me that tou have a ring out of place. Patience and follow my previous instructions, it will come off.

 

[carhartted]

When I looked at it this morning I noticed a peice of ring sticking in the intake port. I belive with paitence I will be able to position the ring so it will clear the port. Thanks for all your help.

 

[carhartted]

Well I got the piston out today, and like I thought the rings were broken.

I know there are two different rings that can go into a 031 and was wondering if you guys could help figure out which one I need.

It is a Stihl 031 AV electronic, inside the piston is the numbers 044, 013, and 1275.

Thanks

 

[stihltech]

rings

Measure the piston. It is metric. This should get you the correct rings for the piston.

 

[carhartted]

thanks stihltech