Ax-Man
Don't make me chop you
It has been awhile since I started a thread so with it being a dull rainy Saturday night I figured I might as pass this little bit of info along.
Ever run a Stihl saw and for no apparent reason it just starts to run a little squirrely. You start to ask yourself what the heck is causing this problem, is it a carb problem? crank seal going bad ? or does it have an ignition problem. More than once it turns out to be a simple fix. Darn spark plug is loose in the cylinder head. It is easy to overlook because the saw acts like it could be a different problem. It really doesn't back out enough to really cause a compression problem but enough to make a saw not idle quite right or an acceleration problem or if you have an ear for ignition it can make it sound or feel like it has a miss in it.
This doesn't happen often and doesn't seem to be model specific but has happened often enough to be one of the first things to check on a saw. I am not a big believer in changing sparks because a bad plug is rare and very seldom the problem in a bad running saw. Spark plugs are good to give you clues as to what might be wrong with a saw like it is running to rich or lean. I will pull one out just to see how it looks that is about as far as I go these days . If it looks good and the tang and insulator base are in good shape it stays in the saw.
I know some of you are saying " Ax-man why don't you just tighten that plug down more to fix that problem or you have a thread problem in the head" To answer that one. I always start my plugs by hand to avoid cross threading and continue to thread them till I can't turn the plug anymore by hand then tighten with scrench. I do it this way to be able to feel how well and how far the plug will thread into the head. I am not a big fan of over tightening a plug but I do snug them down enough to feel that enough torque has been applied to keep the plug from backing out. Even when everything feels good I have a plug that works out a little to cause a running problem once in a blue moon. About the only thing I can say it is just a vibration problem from the saw when it is run.
One model in particular that has this little problem is my aging ms 200's . They get the heck run out of them and also get the most sprocket changing because you have to remove the plug, jam the piston to take off the clutch to replace the sprocket. So there might be some wear in the cylinder threads but even a new plug doesn't solve the problem. I am always thankful a loose plug is the problem instead of a carb replacement. I have also had this little problem on a 66 and most recently a 361 which prompted this thread .
Just thought I would pass this tidbit of info along with checking those other easy little things before assuming the worse if your saw doesn't seem to run quite right.
Ever run a Stihl saw and for no apparent reason it just starts to run a little squirrely. You start to ask yourself what the heck is causing this problem, is it a carb problem? crank seal going bad ? or does it have an ignition problem. More than once it turns out to be a simple fix. Darn spark plug is loose in the cylinder head. It is easy to overlook because the saw acts like it could be a different problem. It really doesn't back out enough to really cause a compression problem but enough to make a saw not idle quite right or an acceleration problem or if you have an ear for ignition it can make it sound or feel like it has a miss in it.
This doesn't happen often and doesn't seem to be model specific but has happened often enough to be one of the first things to check on a saw. I am not a big believer in changing sparks because a bad plug is rare and very seldom the problem in a bad running saw. Spark plugs are good to give you clues as to what might be wrong with a saw like it is running to rich or lean. I will pull one out just to see how it looks that is about as far as I go these days . If it looks good and the tang and insulator base are in good shape it stays in the saw.
I know some of you are saying " Ax-man why don't you just tighten that plug down more to fix that problem or you have a thread problem in the head" To answer that one. I always start my plugs by hand to avoid cross threading and continue to thread them till I can't turn the plug anymore by hand then tighten with scrench. I do it this way to be able to feel how well and how far the plug will thread into the head. I am not a big fan of over tightening a plug but I do snug them down enough to feel that enough torque has been applied to keep the plug from backing out. Even when everything feels good I have a plug that works out a little to cause a running problem once in a blue moon. About the only thing I can say it is just a vibration problem from the saw when it is run.
One model in particular that has this little problem is my aging ms 200's . They get the heck run out of them and also get the most sprocket changing because you have to remove the plug, jam the piston to take off the clutch to replace the sprocket. So there might be some wear in the cylinder threads but even a new plug doesn't solve the problem. I am always thankful a loose plug is the problem instead of a carb replacement. I have also had this little problem on a 66 and most recently a 361 which prompted this thread .
Just thought I would pass this tidbit of info along with checking those other easy little things before assuming the worse if your saw doesn't seem to run quite right.