Cutting with my 372XP yesterday and got to the end of the cut and the log dropped and the saw died. Tried to restart and no luck so checked fuel, it was low so I filled it. It won’t start. Won’t even try. Air filter is clean, I have spark, same fuel I had been using all afternoon. Thought it flooded and have done everything I know to do when they flood. Any ideas?
372XP will not start
- Thread starter SAWFORD79
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Take the muffler off and look at the exhaust side of the piston for vertical scoring marks
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What exactly happened when the end of the log dropped off- did it suddenly pinch the chain or anything similar whilst the saw was at WOT?
First step this^^^
the log was about an inch off the ground and when bar went through it all fell so yes temporarily pinched the bar but saw came right out of cut. I checked the flywheel key and its good.
I did as you said. Yes to my surprise there is a lot of vertical scoring and scraping. Lots of hours on this saw but meticulous maintenance but heavy use since 2009 with no issues other than bars and chains and filters. I did notice that one of the bolts on the inside of the muffler had come out and gasket was blown out and plate between muffler and cylinder had moved slightly and was not allowing for full exhaust. Would this issue have caused this. My big surprise is saw was starting good and running like a champ until it quit.
I’m guessing it was just tuned too lean for a long time. Or an issue with the fuel filter, fuel line or carb diaphragm went unnoticed and it leaned out
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Not that the muffler bolt had a lot to do with it, unless it let a muffler bearing go- meticulous maintenance and missing bits- don't really go hand in hand.
Vertical scoring up the face of the piston over the entire exhaust port usually indicate lean condition.
Vertical scoring up the face of the piston over the entire exhaust port usually indicate lean condition.
sand sock
ArboristSite Operative
on flooded saws, i did this yesterday and a few times before. hold onto the trigger and pull the cord. you may have to do this a few times . but so far the trick has always worked. it was a bit warm out sitting in the truck and i could hear the fuel off gassing high pitch. well that fuel was going into the cylinder. that was with a cold start, 2 -3 pulls and it smoked for a bit , but ran fine . you may have to feather the trigger, to work the fuel out.
spuldup
ArboristSite Operative
"Heavy use since 2009" means it's time to take the top end off and give a good inspection. Saws, like us, live life as a constant wearing out process. Fortunately 372 parts are plentiful. Not so much for us...
Please help me with my ignorance. Saw has always started and ran very well. I understand the theory most people have of if it aint broke don't fix it. If this was/is a lean issue how do I know when its running lean? I will admit I have not changed the fuel filter. Have kept the air filter clean, and have done nothing with the carburetor since it always started and ran well. I need all the advise i can get here please.
Could have an air leak at one of the crank seals, that would cause a lean running condition. Not saying that you were doing this but cutting with a really dull chain on top of an air leak could burn up a top end over time or pretty quickly depending on how bad the air leak or chain.
spuldup
ArboristSite Operative
@SAWFORD79 Always listen for a clean sound in a full bar cut and then 4-stroking out of the cut. With 10 saws in your sig I'd be inclined to think you are aware of that, but check out the youtube for many, many sound examples. Tinman's saws has a good simple tuning video.
As mentioned in the previous post, 4 stroking without a load and cleaning up smooth while under load at wide-open throttle is a way to check tune.
Fuel filters, lines, carburetor, screens, diaphragms… They all work best the day they are installed and slowly deteriorate over a period of time. Some will act perfectly for 10 years and then once they’ve had enough, they start to act up
Fuel filters, lines, carburetor, screens, diaphragms… They all work best the day they are installed and slowly deteriorate over a period of time. Some will act perfectly for 10 years and then once they’ve had enough, they start to act up
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