372xp has run afoul

[woodchuckcanuck]

This has been my tried and true saw. Been running it every day this past month for a couple hours each day blocking firewood. The only change I made recently was to pick up a bottle of Echo brand fuel mix. I still keep the ratio 40:1 as I've always used. Today it was running off and on for a couple hours and I set it down to idle for aboiut 2 mins while I was moving blocks of wood. It just stopped, figuring it was out of fuel I took a look and it was quite low so I filled it up. I could not get it to start again. Normal it runs after 2-3rd pull. Air filter was changed last week. Looked ok. So I checked the plug boot, seemed to a little loose so I buttoned it down and tried again. Tried with choke but after 6-7 pull there was so sign of life. Closed the choke and pull the cord about 10 times. Nothing. I took off the spark plug and it looks like this. Note a great pic but you get the idea.


Only other thing its also been doing lately is running high idle after letting go of the throttle. I did a tweak of the low idle screw a few days back as suggested by @chipper1 . Did seem to help for about a day but its back to doing it again. I am wondering if its the new oil mix that's the issue or something else. Thoughts anyone?

 

[Jethro 2t sniffer]

Compression still feels normal? Does it have spark? Hi idle sounds a worry as could be an air leak. Orr it just might need a carb kit thrown in. Did you adjust the low jet or the idle screw?

If its got spark set the low and hi at factory spec and see what ya get. Watch a couple turning videos if it runs.

If spark is there and lots of Compression it's time to pull her down n sus it out. Could be split fuel line or impulse. Could be the fuel filter has fallin off. Lots of could be's

It's just a saw don't be afraid to tear it down.

Also if Compression is sad pull the muffler and have a gander. It could of been an air leak and its fried. Hopefully not

 

[woodchuckcanuck]

Compressions seems ok. But, I did notice that on the 6th pull the compression was very light, then teh next pull seemed normal. Noticed that a couple times.
Haven't check spark yet.
When I did the adjustment I first adj the L and it had little affect so I adj the the idle screw some.
I'll check vids. Thanks.
Haven't done a tear down before. Well I have actually, when a 353g cylinder went kaput a couple years back. It's still in pieces in a box. But I'll pull off teh muffler and see what its like. Maybe tomorrow.

 

[NSEric]

The spark plug looks fouled to me, there's carbon covering the electrode.

 

[SteveSr]

Only other thing its also been doing lately is running high idle after letting go of the throttle. I did a tweak of the low idle screw a few days back as suggested by @chipper1 . Did seem to help for about a day but its back to doing it again. I am wondering if its the new oil mix that's the issue or something else. Thoughts anyone?

This is usually a sign that it is too lean coming off of load. Look for an air leak or fuel problem. At this point I would also pull the muffler and check the piston.

 

[steele_109]

Hi that plug is terrible clean it or replace it.One of the most common problems with a 372 is the intake boot rips on the bottom check it before you run it again.I have a dozen or more 372s and have run them a lot and none of the plugs look like that.In my time running saws cheap oil or too much in the mix causes that.The plug looked dry if you had pulled it as much as you said you did it should be wet,so you have a fuel deliver problem or a bad air leak.Or maybe both you can get a boot and seals cheaper than a saw.As the guys told you check the muffler first it maybe scored already.But the silver lining to this black cloud is there is always help if you need it the guys on here will be more than glad to help.

 

[woodchuckcanuck]

Got it fixed.

Now earlier in March I had noticed the spark plug wire was chaffing against the plastic cover.



The insulation had almost worn through so I had applied some black tape.

Today, I took off the cover over the air filter, then the top cover. Took a look around and first I checked the spark plug again. Specs for the saw say to set the gap at 0.05 and it was way beyond that. Reset the gap and before reassembling the covers, I started it on the first pull. Good sign. Put it all back together. Pulled to start and no go. Pulled 10 times. No go.

Took off the covers again. Started on the first pull. Put the covers back on. Pulled to start. No go. So something was going on when the covers went on.

Took the covers off again and while running I grabbed the spark plug wire where the chaffing had occurred and immediately got a shock. Closer inspection showed the vibration wore through the black tape and the remaining wire insulation and was shorting out on the top fin of the motor.

Put new electrical tape on and fussed with the wire some to get it in a better spot and away from the fin of the motor. Put the covers back. It started on the first pull.

There you go. Electrical issues.

 

[huskihl]

Red Armor is a thicker oil than most. You should slightly richen your jetting to make up for it if you were tuned on the edge. It looks like the red Armor is cleaning up the carbon left behind by your old oil and a piece of carbon bridged the gap in your plug

 

[steele_109]

Glad you got it figured out,those are very good saws.That's about all I use anymore.

 

[woodchuckcanuck]

Red Armor is a thicker oil than most. You should slightly richen your jetting to make up for it if you were tuned on the edge. It looks like the red Armor is cleaning up the carbon left behind by your old oil and a piece of carbon bridged the gap in your plug

Red Amour I've never seen around here. This is what was available from the Echo dealer I visited.