Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Stihl => Topic started by: ggross on May 16, 2017, 03:29:20 pm

Title: Piston ring instalation
Post by: ggross on May 16, 2017, 03:29:20 pm

Folks, has anyone experienced the piston rings stick after initial installation?
Title: Re: Piston ring instalation
Post by: Cut4fun . on May 16, 2017, 06:47:47 pm
Using oem or aftermarket? 

Never had any problems like that with oem, meteor or caber rings.   

Using a cheaper aftermarket?
Title: Re: Piston ring instalation
Post by: ggross on May 16, 2017, 06:55:08 pm

This was a new meteor cylinder & piston assembly. After the first pop. the rings stuck. I'm now having to start all over again.
Title: Re: Piston ring instalation
Post by: Cut4fun . on May 16, 2017, 08:20:47 pm
Never seen that on a new set. Yet
Title: Re: Piston ring instalation
Post by: Jacks54 on May 16, 2017, 11:45:40 pm
hows is cilinder looking??
Title: Re: Piston ring instalation
Post by: 3000 FPS on May 17, 2017, 10:43:57 am
Nope never had that happen to me either.    Must be an oddity with the piston and rings.
Title: Re: Piston ring instalation
Post by: Cut4fun . on May 17, 2017, 02:26:15 pm
Now I have taken piston scored etc with stuck ring. Took small file and cleaned the edges back up etc. Then used emery cloth inside the groove to finish with. Then install new ring and make sure everything is working freely. Never had a problem this way.

Did you check ring on piston after installing it?
Title: Re: Piston ring instalation
Post by: srcarr52 on May 17, 2017, 03:08:46 pm
Did you check your squish clearance? Stuck rings often happen from the ring land being crushed from the crown contacting the squishband.
Title: Re: Piston ring instalation
Post by: ggross on May 22, 2017, 01:51:35 pm
I plead my ignorant. What is the squish clearance?

Any additional recommendations for solutions? Both from P&C assembly's were both from Bailey's.
Title: Re: Piston ring instalation
Post by: Cut4fun . on May 22, 2017, 02:48:12 pm
https://en.wikipedia.org/wiki/Squish_(piston_engine)

(https://upload.wikimedia.org/wikipedia/commons/thumb/8/8f/Squish_band.svg/220px-Squish_band.svg.png)
Title: Re: Piston ring instalation
Post by: ggross on May 22, 2017, 02:51:37 pm

Do you reduce the clearance by using a difference base gasket?
Title: Re: Piston ring instalation
Post by: Cut4fun . on May 22, 2017, 02:54:59 pm
Yes or none at all by pulling gasket and using something like dirko HT or threebond 1184 1194 etc.  But you must always check clearance when making changes.

Thin copper sheet has been known to be used too. 
Title: Re: Piston ring instalation
Post by: Cut4fun . on May 23, 2017, 01:51:26 pm
Another pic showing squish for ya.