stuck piston ring
#1
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stuck piston ring
I recently got a very nice Enya 60IIIB with a single ring. It had no compression due to the stuck ring and I have tried the following:
15 hours in a warm crockpot/antifreeze
24 hours in Acetone
300 degree oven
all without success. I accept that I will likely need a new ring, but right now I can't even get it off the piston, (short of hammers and vice grips!). I'll be ticked if I have to buy a piston too - this one is in great shape otherwise.
Any ideas?
Martin
15 hours in a warm crockpot/antifreeze
24 hours in Acetone
300 degree oven
all without success. I accept that I will likely need a new ring, but right now I can't even get it off the piston, (short of hammers and vice grips!). I'll be ticked if I have to buy a piston too - this one is in great shape otherwise.
Any ideas?
Martin
#3
RE: stuck piston ring
i agree,,,, ive had several ringed engines that i thought were shot, after years of neglect and improper storage that have come back to life with compression after starting them..... the heat will let the ring expand against the cylinder wall... one being a ST51 a saito 91 Saito 120 and a few others
#5
RE: stuck piston ring
I think it's worth a try at running it although I'd use a healthy dose of castor to be on the safe side. The ring will be stuck at the size of the bore so most of the expansion will be of the piston pushing the ring even harder against the liner, hence the use of castor. Any clearances around the ring will be full of old gummed castor and that's what needs to be softened and get some of it squeezed out by the expanding piston. I've had success at freeing a ring by squeezing very hard with a fingernail alongside the ring gap pressing the ring further into the ring groove. Once one end of the ring starts to move just a little then any solvent like acetone or fuel will begin to get drawn in to the ring groove by pressing and releasing and it'll work its way all around until the other end of the ring frees up.
#7
RE: stuck piston ring
Try soakiong it in fuel or denatured alcohol.
If you are planning to replace the ring, you should be able to force a very small jewlers screwdriver in the ring gap and break it away.
If you are planning to replace the ring, you should be able to force a very small jewlers screwdriver in the ring gap and break it away.
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RE: stuck piston ring
Update on stuck ring - Vince et al suggested just applying a starter until it started. Downunder cautioned to put some castor in the cylinder, (I added 3 drops in the glowplug hole) but it worked! It took about 10 seconds on the starter before it fired. After about two minutes running, I shut it down due to a loosening muffler. The compression was better. Fired it up again and ran for another few minutes. The third start was a hand start after 4 flips.
I'm using some old Cool Power fuel, (18 months), with an extra 6 oz. of castor for running older engines. Rpm was 11,000 with a Rev-Up 11 X 7 1/4. It's a little low but I think fresh fuel will help.
I probably should still replace the ring, but I'm happy just to get it going this well.
Martin
I'm using some old Cool Power fuel, (18 months), with an extra 6 oz. of castor for running older engines. Rpm was 11,000 with a Rev-Up 11 X 7 1/4. It's a little low but I think fresh fuel will help.
I probably should still replace the ring, but I'm happy just to get it going this well.
Martin
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RE: stuck piston ring
So I assume that the ring is now free due to the compression rise?
The best penetrating solution that I have ever used is a 50/50 mix of ATF and acetone and is what a lot of old time mechanics use.
Cheap as chips and works fantastically. Just soak for 24 hours, remove and wiggle or tap - repeat until free.
The best penetrating solution that I have ever used is a 50/50 mix of ATF and acetone and is what a lot of old time mechanics use.
Cheap as chips and works fantastically. Just soak for 24 hours, remove and wiggle or tap - repeat until free.
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RE: stuck piston ring
I have yet to pull the engine apart again, but I am assuming that the compression came back because the ring is free. I can see the ends of the ring through the exhaust port now, about 120 degrees from where it had stuck.
Martin
Martin
#12
RE: stuck piston ring
Good stuff, and if you can now hand start it easily I wouldn't bother pulling it apart again. Obviously the ring is now free enough to start rotating in the groove which is quite normal. I run mine with 25% all castor but that's just me .