MS261 black oil around and under muffler

[Azrel2]

Good morning all,

I just picked up a 2019 MS 261 off of Craigslist for 450$. 20 inch bar, 2 brand new chains, new filter, new plug. It appears to be very lightly used and in immaculate shape. Piston seems clean too. Broke it down when I got home and the saw is 99% percent clean other then specs of black oil on the bar and case with a small to medium amount of black oil on the muffler and underneath it. The guy I bought it from said he bought it from the shop new and ran it lightly with no mods. I would said I'm one step up from him on my knowledge of small engines and chainsawz; maybe an apprentice?

Anyways, there is the back story, the saw started fine and ran fine but I have ran a tank through it yet. Below is a picture of the problem. I'm not too worried but I'd like a second opinion from you guys because you're the best.

Thanks in advance?

P.s: I did already search for an answer to this, including this thread.

https://www.arboristsite.com/community/threads/oil-coming-out-of-muffler-threads.304769/

 

[SteveSr]

Doubtful that this is a oil tank-to-cylinder link. If you had such a leak you would be fogging mosquitoes with the exhaust.

Most likely carbon burning off from the cheap oil / gas that the previous owner used. It could also be tuned rich or the air filter clogged making it run rich. Is this a carbureted or an M-tronic saw (Model -CM)?

 

[Azrel2]

Thank you for the response.

It is carb operated.

Has a new filter and only smoked a little at startup. Maybe he let it set. I'll clean it up and put new fuel in it.

 

[mountainlake]

Quit letting them idle too long. Steve

 

[Azrel2]

Quit letting them idle too long. Steve

Was that addressed to me?

If it was, I just bought the thing 2 hours ago and only fired it up once.

 

[mountainlake]

It was addressed to everyone who runs a saw. For sure not your fault on this one. Steve

 

[angelo c]

Pretty common to happen with a pig rich saw or one that sat for a long time with too much fuel in the case. Possibly from a stuck or misplaced metering lever in carby. Run it a bit and see if it goes away. Retune it too if needed. Report back with results

 

[cookies]

can be caused by not running it at wide open throttle under load, too many short runs and not heating it up all the way, repeated flooding, low quality oil that does not burn properly. Work that saw hard and burn all that excess oil out of the engine block and muffler.

 

[ballisticdoughnut]

Clean it and then go run it hard. It'll clear right up.