Black oily engine deposit

[Big Woody]

I have a new Solo 55 cc 2 cycle that said use 25:1 for 5 tanks to break in then 50:1. I used Echo power blend at 24:1 and had a lot of the black oily slime on the piston after only 1/8 tank and plug was black. Switched to racing 2t at 32:1 and more of the same. So bad it fouled plug and engine has quit twice. Pulled the pop can style muffler and it was full of this black oily sludge. Only have used less than 2 tanks of fuel so far.

Is it from too rich a high speed setting, still too much oil, spark plug problem or what?

Never had this happed before.

 

[Stumper]

Considering all the years that I ran 16/1 and all the more recent years at 32/1 I doubt that the fuel/oil ratio is the problem. I have one two cycle engine that spooges like mad-a cheap weadeater hedge shearthat has limited adjustments. I suspect that your carb settings are off. Also, meaning no offense, but it is important to run saws wide open when cutting.

 

[Al Smith]

I am kind of thinking the same thing.My dear old pappy ran his old outboards at 16 to 1 and never fouled a plug that I remember.I can remember in my teenage years running oil rich mixes,they were a bit hard to start and smoked a lot but didn't foul plugs.

 

[jokers]

I think Stumper has the answer, poorly adjusted Hi speed and possibly partial throttle operation of the saw.

Here is a pic of a black oily deposit on a piston which is from blowby, probably caused by rings that were clipped in a modified port that wasn`t beveled afterward.

The second pic is the exhaust side of the barrel, notice how evidence of exhaust gases is present all the way into the crankcase. Those gases never should have gotten down there. Beside the obvious compromised compression, how do you suppose the intake fuel/air mixture combusts when diluted with exhaust gas?

Russ

 

[cuttinscott]

The problem with any mix richer than 50 - 1 is no fault of the engine or much of the carb adjustment's the so called gasoline we are using today is the problem. Back in the day pappy ran 16 - 1 or even 32 - 1 the fuel was much more combustable than todays fuel. So when you mix richer than 50 - 1 you are killing the flammability of the so called gas. Another point always use the freshest gasoline you can the longer it sets the worse it is......


Just my opinion take it as you will

Scott