Post by jbird on Mar 23, 2021 13:42:27 GMT -6
So I have a sthil MS 250 chainsaw...runs fine, been everything I could ask for. however...recently it has been acting weird and I seem to have fixed it...but I don't know what I did. You see I have a MS250 that I burned up the engine...because someone forgot to put oil in the gas and run about 2 tanks thru it and fried it. So I kept it for parts.
So what it was doing... It was running loudly at the sprocket and even smoking a bit, which it shouldn't do. And either at idle, under load or whatever the chain would simply lock up almost like someone thru the chain lock...but I did no such thing. It was very difficult to even move the chain by hand. But eventually you could and it would run for 15-20 seconds and lock the chain up again. And you could hold the engine tot he wood and no chain movement.
So my thinking was/is that the tensioner and how it works is helping put the bar/chain in a bind. There is a little plastic piece on the end of the screw that seems to want to wander it's way out against the bar and maybe put lateral pressure on the bar. I also thought that maybe the clutch was going bad some how. So when I dug into it...I replaced the tensioner assembly and the sprocket/clutch cover. Things seem to be fine for now....but I am not sure if I fixed it or just got lucky. I did notice that all the springs on the clutch seem good and work fine. I greased the roller bearing, I also removed the "brake dust" from the inside for the sprocket/clutch cover as well. I also notched that the sprocket is a slightly different design as well. Has all the same markings, off the same model saw, just an older version I guess.
Any way I am hoping someone here has some hand-on experience with a similar issue and can shed some light on what the actual problem may have been. I prefer fixing things myself if I can. I hope to have it out over the weekend and we will see if I actually "fixed" it or not....
So what it was doing... It was running loudly at the sprocket and even smoking a bit, which it shouldn't do. And either at idle, under load or whatever the chain would simply lock up almost like someone thru the chain lock...but I did no such thing. It was very difficult to even move the chain by hand. But eventually you could and it would run for 15-20 seconds and lock the chain up again. And you could hold the engine tot he wood and no chain movement.
So my thinking was/is that the tensioner and how it works is helping put the bar/chain in a bind. There is a little plastic piece on the end of the screw that seems to want to wander it's way out against the bar and maybe put lateral pressure on the bar. I also thought that maybe the clutch was going bad some how. So when I dug into it...I replaced the tensioner assembly and the sprocket/clutch cover. Things seem to be fine for now....but I am not sure if I fixed it or just got lucky. I did notice that all the springs on the clutch seem good and work fine. I greased the roller bearing, I also removed the "brake dust" from the inside for the sprocket/clutch cover as well. I also notched that the sprocket is a slightly different design as well. Has all the same markings, off the same model saw, just an older version I guess.
Any way I am hoping someone here has some hand-on experience with a similar issue and can shed some light on what the actual problem may have been. I prefer fixing things myself if I can. I hope to have it out over the weekend and we will see if I actually "fixed" it or not....