372xp won’t start

[BigRon]

My 372xp has been a very reliable saw.

 

I was cutting with it a few days ago and it got very hot, smoked and cut out.

Now it won’t start and is giving a pop when choked, and again as if it has fired with no choke.

 

Ive cleaned it thoroughly, replaced spark plug. To no avail.

 

Any initial thoughts?

 

thanks

[openspaceman]

If you suspect the overheating may have damaged the piston and rings take the exhaust off and check their condition, a photo would help.

[Stubby]

1 hour ago, BigRon said:

My 372xp has been a very reliable saw.

 

I was cutting with it a few days ago and it got very hot, smoked and cut out.

Now it won’t start and is giving a pop when choked, and again as if it has fired with no choke.

 

Ive cleaned it thoroughly, replaced spark plug. To no avail.

 

Any initial thoughts?

 

thanks

Sounds like it has nipped up . Did it over rev slightly just before it stopped ? Could be and air leak causing it to run lean . All speculation until you get a look at the piston .

[spudulike]

Second what they said. The overheating suggests running lean leading to seizure. You should be able to tell lack of compression from pulling on the starter handle but removing the muffler should give you the full picture.

Most likely the impulse line has come off. I did a US ported one some time ago where this happened, the saw had destroyed its crank and shows that porting does protect the cylinder but the overrevving caused other damage.

[BigRon]

Thanks all for your input. I did look at head of piston through the spark plug and it didn’t look too bad.

Quite a bit of carbon fouling on the spark plug itself though?

I will try and get a picture of the bore tomorrow and post it.

[Stubby]

1 minute ago, BigRon said:

Thanks all for your input. I did look at head of piston through the spark plug and it didn’t look too bad.

Quite a bit of carbon fouling on the spark plug itself though?

I will try and get a picture of the bore tomorrow and post it.

Its the piston skirt you need to have a gander at .

[spudulike]

You can look down the plug hole on some saws but forget the piston crown, drop the piston to BTDC and look at the cylinder bore above the exhaust port. I used this method as a very quick check and it is effective especially if you have a small head LED inspection torch.

[BigRon]

Pictures for you all… you’re going to tell me it needs a full rebuild 🤣🥲

[BigRon]

22 hours ago, openspaceman said:

If you suspect the overheating may have damaged the piston and rings take the exhaust off and check their condition, a photo would help.

Photos on thread now sir

[Stubby]

2 hours ago, BigRon said:

Pictures for you all… you’re going to tell me it needs a full rebuild 🤣🥲

Piston looks a bit scuffed up and maybe the ring is stuck . So it has nipped up . The bore is probably salvageable at a guess . New OEM or aftermarket piston OEM gudgeon pin clips  and remove any aluminum transfer from the bore with brick acid or similar . Light hone . This is all guess work though without seeing the bore .   Edit : Oh and find out what caused it in the first place , bad/old mix or air leak from somewhere . Fix that or you will be here again . 

Edited yesterday at 17:53 by Stubby