372 scored piston

[gwat]

What made my 372 lean out?  Is it as simple as a carb rebuild or do I need to dig deeper?

This piston is a little worse for wear on the exhaust side.
I'm guessing I should really replace the piston & cylinder..?



 

[ladylake]

 That side of the piston is not scored.  Steve

[Tacotodd]

In my opinion, it’s barely scuffed. Another 1/8 to 1/4 turn rich aren’t going to hurt anything considering what I see. I think you’ve caught it in time.

While you have everything apart, look at the carb. Does it have the proper tension adjustment screw spring still in place?

Did you vac/press test before the tear-down?

What made you suspicious in the first place? 

What’s the spark plug look like?

[Al_Smith]

You can scorch them from a restrictive exhaust also .I would say a  little work on the muffler might alleviate that problem at the risk of having people jump back in horror at just the mere  mention of it . :D Not to worry we have no chainsaw police in this part of Ohio ,I'm good to go .

[weimedog]

Think that top end looks typical of the breed, plenty of life yet. If it's gone lean to the point you see a BIG difference from one day to the next, the very first thing you do on those X-torq's is a brake clean test or spray brake clean under the clutch cover and see if it effects anything. Fire it up with NO bar and chain, Pto cover off is best, Spray some brake clean at the clutch area. If that saw shuts off  you found the answer to your question, if NOTHING happens... take a breath , relax,  and do the typical checking fuel lines, filter etc. of course after simply giving it a bit more fuel. You will need the proper carb adjustment tool. eBay that. I'll drop a video showing the "brake clean test"


Jonsered cs2165 48mm Part 1 of 5 & Brake Clean "Air Leak" Test Demonstration On Husqvarna 576xp - YouTube

[ladylake]

  
Also spray some at the carb boot, the other seal and the base gasket.  Be careful not to get it in  the carb when spraying at the carb boot.   The easy way to test for a air leak.  Steve

[Al_Smith]

When they used propane as a propellant WD 40 would do the same thing .Fact it actually made a good alternative for starting fluid .Every so often somebody would oil the gas tank by mistake .The WD 40 treatment made quick work of fixing that problem .Smoked a little but settled right down after it had fogged the area for mosquitoes .

[Stoneyacrefarm]

Oil the gas tank?
Cmon.   
We would never do that!! 8) :D

[Al_Smith]

I have and put a chain on backwards ---several times .Had two saws stuck in the same tree .

[sawguy21]

Oil the gas tank?
Cmon.  
We would never do that!! 8) :D

It happens. I have done it on small Echos, the front tank is for fuel unlike most saws.

[Al_Smith]

My dad  RIP oiled his gas two times in the same week on his old Mac pm 610 .Of course he was 82 at the time which might have had something to do with it. He's still run that saw but got help from his grandson .The old Mac was getting a little heavy for him .I took a lighter saw for him to use .

[gwat]

Think that top end looks typical of the breed, plenty of life yet. If it's gone lean to the point you see a BIG difference from one day to the next, the very first thing you do on those X-torq's is a brake clean test or spray brake clean under the clutch cover and see if it effects anything. Fire it up with NO bar and chain, Pto cover off is best, Spray some brake clean at the clutch area. If that saw shuts off  you found the answer to your question, if NOTHING happens... take a breath , relax,  and do the typical checking fuel lines, filter etc. of course after simply giving it a bit more fuel. You will need the proper carb adjustment tool. eBay that. I'll drop a video showing the "brake clean test"


Jonsered cs2165 48mm Part 1 of 5 & Brake Clean "Air Leak" Test Demonstration On Husqvarna 576xp - YouTube

Thanks!  I'll put it back together and spray some brake clean under the clutch.  Fingers crossed...

[Stoneyacrefarm]

Oil the gas tank?
Cmon.  
We would never do that!! 8) :D

It happens. I have done it on small Echos, the front tank is for fuel unlike most saws.

I've done it twice in my lifetime so far. 
First time I caught it right away. 
Dumped everything out on the ground. 
Second time not so lucky. 
Didn't have any mosquito issues for a little while on the second time. 😂😱