Stihl chainsaw almost locked up-?

[Diamondpilot]

Others gave good suggestions but I would check the pull rope/clutch area.

Chris

 

[Carykong]

I have gotten by old mecury 25hp outboard going after sitting for over two years with old gas with Sea Foam Gas additive. Just a few spoonfuls in the bowl and the remainder in the gas tank. Ran just like the day I bought it new in 1988,

 

[Gary Fowler]

If it spin freely with the plug out but not when it is in and you havent changed out the plug for a longer one, the the problem can only be one thing and that is the compression is building up with no where to go, Pull the muffler and check the exhaust reed valves. Maybe a dirt dauber plugged up the whole thing. It almost has to be in the exhaust not getting out.

 

[DennisMI]

Could it be a sheared flywheel key?

 

[tree farmer]

I'm thinking rust or other corrosion has formed on the rings or cylinder wall, especially if the saw was stored in a damp area. If that's the case, I would pull the plug and shoot a little penetrating oil in the spark plug hole, then turn the engine over a few times with the plug out. Now tip the saw over and dump out the cylinder. Check the appearance of what comes out. If that doesn't work, you're gonna have to pull the head....Dan.

 

[BigE_]

My Stihl 036 was doing that for a while, really hard to start, really hard to pull the cord. Almost hurt to pull the cord. This was after leaving it sit with gas in it for 4-5 months.

I dumped all the gas out, bought fresh premium, mixed it with Stihl oil, finally got it running and ran it hard, never had any problems with it after that. Maybe I just got lucky, though.

 

[Dave5264]

Not familiar with this particular stihl saw, but is it at all possible for mice tohave gotten into the muffler?

it doesnt take much for them critters to get in , if you can put a pencil thru the gap/hole in the muffler /exhst opening, a mouse can get in.

id take the muffler off, and see if it turns over

 

[BXpanded]

If I understand, the rope is very hard to pull.
Unless I missed it somewhere, the op hasn't said...
Is the rope hard to pull when the sparkplug is removed?

If it is, it's likely rust on the cylinder wall, assuming that engine has an iron cylinder liner.

When you look down the carb throat you're probably seeing a reed valve. If it moves, it isn't stuck. A stuck reed valve (in the unlikely case that it could stick closed) would make it easier not harder to pull the rope.

 

[Ford850]

OP said it was easy to pull with the plug removed. As some others have suggested, check the muffler. Mud wasps get into the muffler and build a mud nest plugging the exhaust. I've had it happen to me, and I suggested it for another poster some time back and it was the cause in that situation too.

 

[woodchuckie]

I don't know what the problem is with mine but at times after it's set for a while it's hard to pull like the exhaust valve isn't exhausting. I take the plug out and it's easy to pull. I put the plug back in and it pulls normal and runs like it should.