My chain saw starts but won't keep running what is wrong with it

Chain adjusted too tight?
Chain Brake loaded with saw dust?

Replace the fuel filter in the tank, if there is any sign of leaksge on the fuel hose replace this as well

if it is hard to start and smokes sounds like the fuel is to old and the oil to gas mixture is wrong start off with some fresh fuel gas is only good for 30days in small engines

Had this happen to mine when I was limbing stuff that was too small. I know better. There is probably a burr on one or more of the guide portion of the links where they run in the bar. This causes that link to be tight in the bar at this point. The chain probably hit something on the body of the saw when it flew off. Take the bar off the saw and run the chain through the groove in the bar. If you have any links with nicks, they will bind, causing the chain to stick and not run freely. Once you've identified the problem links you can remove the nicks using 120 grit paper backed up with a flat piece of steel so you only remove the high spots.

I recently bought a brand new 372XP and spent the first day trying to start it as per the instruction manual with no success, never even fired once. Removed the plug to find plenty of fuel and that the plug has a good spark. Left it until the next day mainly to allow my arm to recover (& scour the internet for clues). I found a forum that said not to use the decompressor and sure enough without the use of the decompressor button it fired first go with the choke on then I reset the choke & it ran properly on the second pull. The decompressor button can be reset with fine nosed pliers or removal of the top cover by undoing three screws. Good luck it's a great saw once you know how to start it.

Check to make sure the blade is not installed backwards. It's an easy mistake to make, everything will work OK, but the saw won't cut if the blade is on backwards.

Replace the fuel filter in the tank, check the fuel hose up to the carb for signs of leaking, if so replace the line, between the cylinder and the carb back plate is a rubber induction tube, make sure this has no split.

If you have a good spark, and there is fuel at the plug, the only things to stop it fireing up are a sheared flywheel key knocking the timeing out, or the engine has low compression due to wear or damaged piston and ring.

Sounds like your chain is to tight.Take the cover that is at right side of the saw motor off and loosen the two nuts a bit and look for a tension screw behind the bar and back it off,if the bar won't move loosen the two nuts that hold the bar on the saw.With the saw siting like you use it pull down on chain and get about 1/8 of an inch between the bar and chain.(use gloves)If the bar is blue by the chain groove You will need a new bar.Blue means the bar has over heated and lost its temper.The blue metal is brittle in other words.You should all so check the drive sprocket for wear.

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