Freeing stuck rings

[Jasonrkba]

I have a poulan 3400 with low compression. I'm suspecting the rings are gummed up and stuck in the grooves. Has anyone been successful spraying anything down the plug hole and soaking them free? The spark arrestor was as gummed up as I have ever seen also.

Thanks. Jason.

 

[ammoaddict]

I have a poulan 3400 with low compression. I'm suspecting the rings are gummed up and stuck in the grooves. Has anyone been successful spraying anything down the plug hole and soaking them free? The spark arrestor was as gummed up as I have ever seen also.

Thanks. Jason.

Have you pulled the muffler off and looked inside?

 

[Jasonrkba]

Looks good.

 

[Jasonrkba]

Head bolts are tight also.

 

[grizz55chev]

Have you done a comp test?

 

[Jasonrkba]

It read about 75.

 

[Jasonrkba]

This saw sat for a very long time.

 

[grizz55chev]

I've heard acetone and atf is a good cocktail that some guys use.

 

[Chevboy0167]

No idea if they work cuz I have not personally used them but.....

https://www.liqui-moly.com/en/us/valve-clean-p000041.html#2001
https://www.bgprod.com/catalog/engine/bg-epr-engine-performance-restoration/

https://www.crcindustries.com/products/marine-engine-tune-up-decarbonizer-13-wt-oz-06121.html

 

[cookies]

take off the muffler and pour berrymans b12 chemtool into the cylinder upside down with the piston at top dead center to soak the rings 24 hrs. try running it until warm, repeat if needed.

 

[Evan]

Ive broke a few light smeared rings loose with a screw drive.
One was a 084 that was slightly straight gassed. Freed its rings then bucked alot of big fire wood while I waited for new piston.
Interestingly I hsd a second 084 recently with a stuck ring. Also freed with screw driver. It did run but bad. Tore that one down did a pretty decent refresh and sold it.

Gota pull muffler to see how bad they are

 

[Pioneer]

Lacquer thinner. Soaked a piston in some recently, the carbon literally fell off. Loosens most varnish and other gunk.

 

[Jasonrkba]

I like the acetone atf combo. I've used it before on stuff but forgot about it. If i gotta pull the cylinder it will get cabers. I'm going down the rabbit hole with this one. The muffler and spark arrestor had that nasty gummy crap that is hard to clean when I had it off. I opened it up while cleaning.

 

[huskihl]

Gummed up, like clean but dry waxy oil?

Or gummed up, like burned hard black carbon locking the rings in place?

 

[thenne1713]

Have you pulled the muffler off and looked inside?

I had a three day old pro saw that the ring stuck w/ a carbon film that looked like MAGIC MARKER, and had to disassemble and break ring to remove. I blamed the 40:1 namebrand dino 2-cycle oil, and now run ONLY synthetic. I was able to clean/ reuse the the Piston... (realizing slightly LEAN maybe had an effect?) MY $12.00 repair, as back had gone out, and sat on shelf three years before I discovered problem. Dealer quoted $640 rebuild w/ new PC Kit; 10+years later, still running strong Milling on namebrand synthetic at 50:1

 

[Jasonrkba]

I've had it on old saws before that have been sitting. Acetone and a brass brush have a hard time cutting it off the spark arrestor. So im thinking the rings are glued into the lands of the piston. I've. Gotten the rings out of saws like that before and cleaned everything up real good and the saws run fine. That was in situations where the rings where harder to find. Im curious if anyone had a "go to fix" when they run into this. Reringing is probably the right fix.... I guess.

 

[Abbeville TSI]

The best fix for a gummed up spark arrestor screen is to remove it and while holding it in pliers, heat it red hot with a propane torch. The crud will turn to white ash and can be brushed off easily.

 

[Jasonrkba]

Im guessing when I get these kind of projects, it was running supper rich. To the point of not running. The owner floods the heck out of it and sets it down for 20 years. Gas sitting in the exhaust turns to varnish with a mixture of oil. For some reason this stuff is easier to clean off of the polished surface of the carburetor but sticks like glue to everything else.

 

[Smitty Smithsonite]

I had a Husqvarna backpack blower in here once - owner said he lent it to someone, and it came back not running. Zero compression. Tore it down and the rings were stuck FLAT into the piston! Piston was BLACK on BOTH sides, AND some of the skirt! That SOB got HOT! Whoever borrowed it probably threw whatever oil they had laying around in it, and none of it was 2-stroke oil. I tried every chemical I have from MEK to acetone to oil, and NOTHING touched these rings! I actually broke one of them trying to pry it out.

Heat was the only thing that extracted the top ring unscathed. Once I cleaned everything up, I threw it back together with the one ring, made some carb adjustments and shipped it. Guy said it ran better than it ever did brand new!

 

[Jasonrkba]

I had a couple minutes to pull the cylinder today they were not stuck, the piston is just flat worn out. Looks like little red barn is the only folks making an aftermarket piston. Guess I'll get that and a set of cabers.