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Post by doktorbert on Nov 6, 2012 19:05:14 GMT -5
I am working on a Homelite DM-50 Concrete Saw that has the 'thin' piston rings and I need to find a set of them. They are Homelite # 69193-A.
Top dollar gladly paid!!!!!!
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Post by doktorbert on Nov 8, 2012 15:41:37 GMT -5
Bumpity-Bump!!!!
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Post by lesorubcheek on Nov 8, 2012 19:10:12 GMT -5
Hi Dok and welcome.
69193-A are rings for a 750 or Super 2100. If you have thin rings on a DM-50, it means a 450 piston was used as a replacement at some point. Its rings are 12309. If you need some 750 rings, there's a couple options. Think most common is to get some Mac 125 thin rings and file 'em for proper gap. Second option is top secret!
Dan
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Post by doktorbert on Nov 12, 2012 10:50:28 GMT -5
Hi Dok and welcome. 69193-A are rings for a 750 or Super 2100. If you have thin rings on a DM-50, it means a 450 piston was used as a replacement at some point. Its rings are 12309. If you need some 750 rings, there's a couple options. Think most common is to get some Mac 125 thin rings and file 'em for proper gap. Second option is top secret! Dan Thank you!!!!! That is a HUGE help in getting this project through to completion!!!! |
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Post by Supercharged86 on Dec 9, 2014 22:49:04 GMT -5
Just picked up a complete '79 DM50 that the previous owner said just stopped running, he figured it was an ignition system problem. Just so happen I had a complete (3 piece) working system from a DM50 parts saw. Figured it was going to be an easy fix. It seems the ignition system is in perfect working order (according to the testing procedures) and I'm guessing it won't fire because it only pulls about 80-90 psi. Pulled the muffler and luckily it's not scored, it's a thin ring version and they must be just worn out. So the question now is whether or not to replace the "thin rings" or swap in the newer thick ring version from the '86 parts saw, which needs both rings too?
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Post by chainsawlady on Dec 9, 2014 23:36:48 GMT -5
Just picked up a complete '79 DM50 that the previous owner said just stopped running, he figured it was an ignition system problem. Just so happen I had a complete (3 piece) working system from a DM50 parts saw. Figured it was going to be an easy fix. Turns out the ignition system is in perfect working order, it won't run because it only pulls 75 psi. Pulled the muffler and luckily it's not scored, it's a thin ring version and they must be just worn out. So the question now is weather or not to replace the "thin rings" or swap in the newer thick ring version from the '86 parts saw, which needs both rings too? I have 2 - 12309 - thin rings in my inventory. chainsawlady |
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Post by sweepleader on Dec 11, 2014 15:56:54 GMT -5
I don't remember who posted this trick but I read it here some time back. Mix 50/50 acetone and automatic transmission fluid, squirt a spoonful or two in the cylinder through the exhaust or spark plug hole. Turn the engine over, let it soak, repeat.
I have used this on a couple of engines and the compression came back. Both run fine now, no rings, no rebuilding, no disassembly.
Not saying it will work on every engine, but it worked on mine. I do it with every engine I get that is balky starting.
Good luck.
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Post by Supercharged86 on Dec 12, 2014 9:25:46 GMT -5
Thank you Sweepleader, Unfortunately, after I torn it down I found the problem. The damage wasn't viewable through the intake or exhaust port. Something like maybe the spark plug electrode broke off and got caught on the transfer port, luckily the cylinder appears undamaged. I have a spare DM50 piston that just needs rings. Hopefully, she will fire up when done. Thanks. Steve  |
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Post by Supercharged86 on Feb 20, 2015 10:06:42 GMT -5
Two new rings equals 170+ lbs compression and she fired right up. Running great now!
Picked up another one, a very nice looking 1980. This one is also a thin ring version with low compression, I'll have to try the secret sauce first. Thanks.
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