you might be right about that. does that mean piston needs replacing?There appears to be material detaching from the piston.
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you might be right about that. does that mean piston needs replacing?There appears to be material detaching from the piston.
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I've been thinking the same, something looks odd.
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It didn't take me that long to take it apart, so I think I want to try and put it back together , clean the carb, then see whats really causing the saw to act that way. Maybe I will clean the carb after I run it after reassembly, just to keep track of any possible changes. Please someone tell me how best to clean up the carbon deposits and what to use to hone the piston and possibly the cylinder ?
Thank you for your long post. Lots of stuff to think about.interesting thread... ...sending Best Wishes! ~
I think there's probably a whole lot of over thinking going on in this thread. First of all, an air leak or bad crank seal can in no way make your saw run like that. Clean the topend and put it back together. Don't sand anything unless you just want to remove the carbon from the piston crown. Forget measuring anything. Your topend is fine. I also would not call that rich. If anything it's running hot and lean and baking the carbon on the crown and CC.
Verify the tank vent is good. Clean the carb. Trim the limiters on the carb needles and reinstall.
I really think it sounds like more of an ignition problem than anything else. Replace the plug and see if that does it.
There IS a whole lot of over thinking going on in this thread. First of all, an air leak or bad crank seal can in no way make your saw run like that. Clean the topend and put it back together. Don't sand anything unless you just want to remove the carbon from the piston crown. Forget measuring anything. Your topend is fine. I also would not call that rich. If anything it's running hot and lean and baking the carbon on the crown and CC.
Verify the tank vent is good. Clean the carb. Trim the limiters on the carb needles and reinstall.
I really think it sounds like more of an ignition problem than anything else. Replace the plug and see if that does it.
>I think there's probably a whole lot of over thinking going on in this thread.
I think there is probably a whole lot of too simplified thinking going on in this thread! we all know a too loose spark plug won't fire up any engine... or ensure an optimized performance parameter...
I honestly feel sorry for this guy. He comes in here asking for help and instead gets led on a goose chase causing him to believe his saw is junk. Misinformation is worse than no information.There, I fixed your first sentence for ya. There really is too much over thinking going on IMO.
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> sandpaper. pistons and rings like nice round, clean oily cylinders. I would not hesitate to run some 600 grit w/dry paper longitudinally using gasoline only as a cutting agent. lightly, just to scrub things up. not to hone! this assumes for next run, same rings. if it was mine and I did scrub cyl once precleaned or carbon and any grits in there, they will all have them... once taken apart... I would not have a problem lightly running the 600 across the face of the rings. I said lightly... and not to remove metal, merely to lightly upset them a skosh. remember, this is my approach, not joes toms or bills, lol who are they? I am an engine builder. with a lot of experience. but I am not a chainsaw engine builder, but I am a tuner, too. i have a lot of dif 2-stroke engine/tuning exp. and I am a very expd porting and carb modifier, too. no -wd40! no baking soda... no need for next run to leave over nite. don't soak it, clean it! and 100% perfectly clean. it must be clean. a good engine builder will open a block of all fittings once machine work completed, air blow thoroughly... maybe vat it... briefly then wash every thing with hot boiling soapy water... to both clean and further degrease... uses spl brushed and spl bore brush... then once done, out side to hose and under water pressure blasts every thing hard. maybe does it all again, too... then once washed with water... air blows it and then uses rosebud on welder and heat soaks entire block to remove any and all moisture... now block is ready for pre-assembly prep and into clean room it goes... well, ideally. in any event u must get it clean, plain and simple. problem areas are in transfers. no junk there! it goes without saying nothing in crankcase, too. -0-!
A dirty air filter does not effect carbon deposits in any way. Oil quality, gas quality, ratio of each, air to fuel ratio, combustion temperatures are all things that affect carbon build-up. The dirty air filter could explain the whisker marks above the top ring and the edge of the piston dome on the exhaust side.I know someone is gong to say something about those carbon deposits, I know I should've cleaned my air filter more often, but is that the only thing that effects that? and how do I safely clean it out?
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