Stihl 041piston lockup at start
- Thread starter Cedar Row
- Start date
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It didn't smoke. but I have since discovered a bar oil leak, ( stuck a q-tip into the cylinder and got oil from the top of the piston) and have replaced the oiler o rings. Apparently I got more oil in the cylinder while installing the oiler, now I have to figure a good way to clean the cylinder.
I also seem to have a problem with the clutch side needle bearing. The sprocket is pretty tight, not sure how loose it should be.
New needle bearing took care of the tight clutch. Rinsed out the cylinder with straight gas. Woodruff key is still large enough to index the flywheel, I assume it's major purpose is indexing since the flywheel is torqued pretty tight on a tapered shaft. Next I will take a closer look at the starter. It pulls easily with no spark plug, but maybe the compression is enough to cause a problem. I'm running out of things to check without doing a complete disassembly.
Pull the plug and pump the oil out. Reinstall plug and give it a shot of wd40 to help it start. DO NOT be shy when pulling it over!. If it locks up again, repeat the process. Hurts when it locks and pulls the starter handle out of your fingers.
How do I know? When I started in 81, I did at least on a month. 041, 051, 070, 075 all use this pump.. Rubber seal, oring, spring and clean the end of the pump body is the repair.
You then want to run the saw a few minutes to clean the oil out. Remember it leaks into the crankcase first.
How do I know? When I started in 81, I did at least on a month. 041, 051, 070, 075 all use this pump.. Rubber seal, oring, spring and clean the end of the pump body is the repair.
You then want to run the saw a few minutes to clean the oil out. Remember it leaks into the crankcase first.
I'' give the restart a try. The oil is out of the cylinder, might be the crankcase causing problems. I'll do some aggressive startup pulls.
Thanks!
Thanks!
I think you diagnosed my problem although I haven't checked to be sure. I've got an ms250 about 3 years, very little use. Usually first time cold it is very hard to pull, so hard that it feels like a hydrolock. sometimes it fights back so hard it jerks it out of my hand....ouch.. After a few pulls its loose like normal but I did notice quite a bit of smoking so I'm guessing now that the chain oil is draining into the cylinder.
That MS250 is a clamshell design, chain oil can’t drain into the crankcase like an old 041.
OK, well, here is what I just did. Went out and rather than start it I left it in off position. Pulled it about 4-5 times, very hard pulling. after that it loosened up. Went to start mode and it easily started up. I was thinking I caused the problem. It has those fancy new filler caps with the Orings. If you fill it totally up and press that cap in there it is going to press that oil somewhere. I'll try letting it run lower on oil turn off then restart. When its stiff on start it will jerk the handle out of your hand before it gets over TDC.
With a little tinkering I got the saw to fire, it ran and smoked a little bit, then quit smoking. The new seals on the oiler seemed to increase the bar oil flow, I turned it down some. Saw seems to be doing OK, haven't cut but one piece of wood so far.
Thanks stihltech! It worked!
Thanks stihltech! It worked!
