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One of the challenging jobs you will come across with your engine is when it loses compression and you have to either loosen or replace the rings to get it back. Don't know what rings are? The rings are metal bands which encircle the piston almost all the way around its circumference. The job of the rings is to make the piston tight to prevent the combustion forces being wasted and by preventing the lubricating oil from getting into the combustion chamber.

This discussion on the SEL shed some good light on the subject revealing various methods which may be of help to you.

 

From: "jo ogborne" This email address is being protected from spambots. You need JavaScript enabled to view it.
Subject: freeing stuck rings 
Date: Tue, 5 Dec 2000 21:25:25 +0800

Has anybody ever used the rubber roller method of freeing stuck piston
rings ?I have a 6 inch diam piston with 4x 2 rings ? 50% are free but
the remainder are well and truly frozen . It has been suggested that if
i chuck the piston and at slow speed run a rubber or nylon toolpost
mounted wheel [like a knurling tool ] over the stuck rings they will
free up and the risk of breakage will be almost non existant. Any
comments ? Needless to say the piston has been soaking in distilate.
Peter and Jo Ogborne
Trigg Western Australia
This email address is being protected from spambots. You need JavaScript enabled to view it.

From: "Joe Prindle" This email address is being protected from spambots. You need JavaScript enabled to view it. Subject: Re: freeing stuck rings Date: Tue, 5 Dec 2000 08:18:13 -0000 No, I haven't tried that one but... I have an air gun ( for blowing dirt off and the like) with a piece of small copper tubing on the end. I clamp the piston and rod assembly in the vise and scrub it down with a scothbrite pad, take a dental pick and dig the crud out of the end gap on the rings and then warm it up with the heat gun.(the piston, not the crud). Once it is warm to the touch I give a little blast down into the end gap of the ring with the air gun and they usually pop loose. Sometime I have to gently "massage" the ring to get it to pop loose all the way around the groove but it is a pretty gentle process, and while I have broken a lot of stuff, a ring has NEVER been one of them. Did have a little "sledgehammer accident" with a mogul piston one time though... Joe Prindle

From: "jo ogborne" This email address is being protected from spambots. You need JavaScript enabled to view it. Subject: Re: freeing stuck rings Date: Tue, 5 Dec 2000 21:49:47 +0800 Yes Joe I'll try that one ,maybe first . Another method was to gently tap the stuck ring with a nylon hammer ,following it around the circumferance . Peter and Jo Ogborne Trigg Western Australia This email address is being protected from spambots. You need JavaScript enabled to view it.

Date: Wed, 06 Dec 2000 08:23:03 +1100 From: RUSSELL GILBERT This email address is being protected from spambots. You need JavaScript enabled to view it. Subject: Re: freeing stuck rings |warm it up with the heat gun.(the piston, not the crud). Once it is warm to |the touch I give a little blast down into the end gap of the ring with the |air gun and they usually pop loose. Sometime I have to gently "massage" the |ring to get it to pop loose all the way around the groove but it is a pretty |gentle process, I did Joes method with both the hornsby piston and the blackstone and they both freed up really well with exception to one ring on the hornsby piston. It has four and one was already broken, two freed up easily but the last; the minute I touched it; broke. It was very brittle and I realy think it must have been cracked already but I'm not totaly sure. The only difference between what Joe did and myself is that once I warmed it up a little I used the kero gun on the air compressor to blow out the crud that was holding the ring in place. As no doubt many have said before, TAKE YOUR TIME! Russell Gilbert This email address is being protected from spambots. You need JavaScript enabled to view it. "why kill only 6?, why not knock 24 of them on the head all at once!"

From: "Reg Ingold" This email address is being protected from spambots. You need JavaScript enabled to view it. Subject: Re: freeing stuck rings Date: Wed, 6 Dec 2000 09:15:49 +1100 I have used this method a few times. NO GOOD with pinned rings! Use a skateboard wheel. If one end comes loose and the ring is pushing it foreward, reverse the lathe or it will surely break. It does work but, you need to watch it all the time. Blink, oh Bugger!! Reg & Marg Ingold. Holmesville. N.S.W. Australia. This email address is being protected from spambots. You need JavaScript enabled to view it. http://www.oldengine.org/members/randmingold

Date: Tue, 05 Dec 2000 22:19:01 +0000 From: Jim French This email address is being protected from spambots. You need JavaScript enabled to view it. Subject: Re: freeing stuck rings Hi Peter On my 5HP Petter M Victory all three piston rings were stuck. I soaked them with penetrating oil and paraffin for a couple of weeks and eventually resorted to heat. I used a 2 pint blow lamp and slowly brought the whole piston and rings up in temperature. When I spat on the piston crown and it turned to steam, I started to intensify the heat around the rings. As the gunge behind the rings carbonised, it expanded and loosened the rings. I just kept rotating the piston with the heat on the rings until they came loose. I left it to cool naturally and thought that the piston rings may have become brittle, but they came off and were as good as new! I don't know if this is the right way to do it, but it worked for me! Jim -- Jim French This email address is being protected from spambots. You need JavaScript enabled to view it. http://www.insulate.co.uk

From: "Jerry Bernard" This email address is being protected from spambots. You need JavaScript enabled to view it. Subject: Re: freeing stuck rings Date: Tue, 5 Dec 2000 20:14:20 -0600 that kinda reminded me when i fixed my friends go kart that had been setting up. the rings were stuck, i was gonna try to spray some WD-40 down the cyl walls, but after a few cranks nil compresson turned into maybe 13 lbs worth, so i told my friend to keep pulling on the rope while i checked the carbureator out. soon built up a VERY good amount, then i fiddled with it a bit and VRRROOM!! but those stuck rings had me puzzled at first.

Date: Tue, 5 Dec 2000 21:24:06 -0500 From: John Culp This email address is being protected from spambots. You need JavaScript enabled to view it. Subject: Re: freeing stuck rings As I mentioned last month, a good spray of "S'OK!" in the cylinder of "Smokey Joe," my old WWII Homelite generator, freed the stuck piston in a few minutes and released the stuck rings in a few minutes more. No disassembly required. :-) I'm not privy to its formula, but it smells like citrus peel oil, just like the stuff they sell in bike shops to clean chains, and I'm positive it's got castor oil in it. I could really smell it on that first startup! John

From: "David Ernst" This email address is being protected from spambots. You need JavaScript enabled to view it. Subject: Re: freeing stuck rings Date: Wed, 6 Dec 2000 04:55:36 -0800 Hot water and lye will do the trick. It will work quicker if you apply a source of heat to the mixture for a few hours. The added advantage is the solution will also clean the lands and remove or loosen the carbon also. Rinse very thoroughly. Dave E

Date: Wed, 06 Dec 2000 07:20:10 -0800 From: Curt Holland This email address is being protected from spambots. You need JavaScript enabled to view it. Subject: Re: freeing stuck rings Sometime ago, parts guy, Tim Crizan (sp?) shared his tip with me for removing stuck piston wrist pins. He simply boils the piston in water until it is loose. Perhaps this would work on piston rings too. Has anyone tried this? Curt Holland Gastonia, NC