So I have been experiencing some oil puking out of my M8 114 air cleaner. So I know some of that is ending up in the combustion chamber. Here are some photos of a piston and a valve. The pistons actually look almost identical so I only included one. On the valve photo there is not much gunk built up on the valve. But notice the oil above the valve seat.

 

How many miles on it ?

 

why did you tear into it?

 

Did they forget the stem seals?

 

I saw the same thing when I opened mine up @ 9800 miles. I believe it's normal operation for these engines. The carbon is terrible for so few miles. I plan to vent to atmosphere when I get my big-bore project finished.

 

Maybe this will help the nay sayers. Good pics

 

4K miles. Photos taken with a $35 endoscope I bought off Amazon. Use with a smart phone. Gonna go to dealership tomorrow and see what they suggest. Bike isn't using any oil other than an ounce or so that the crankcase breathers are putting into the combustion chambers.

 

Don't see any oil on the valve stems. This has to be coming from the crankcase vents. Or at least I think it is.

 

I didn't. Photos taken with an endoscope.

 

It is coming from the breather system. The whole inside intake passages are coated in oil. I also saw some oil standing on the throttle blade.