Piston Wash

[rocks rev]

What compression, elevation and fuel are you running ???? Just seems like both cylinders are very similar in appearance for a crank seal. I chased similar issues only to find that my compression was to high for the fuel and elevation I had. You can jet richer but don't be surprised if you still don't get good wash. If the compression is to high for a given fuel the fuel burns too fast and causes the same looking wash as you have. When you start running a head such as a RKT where the squish clearances are more correct (.045 ish) it seems to be an issue more. The squish velocities speed up and problem is more pronounced.
I backed mine down to 12.5:1 for 1000 ft on premium....

Not sure of exact comp. but atleast 14:1. I ride from 7400ft. and up, and use premium (91 supposly) All these pics are the Mag side, the PTO side looked the same other than the Locator Pin went and the ring spun/hooked the Exh. port.

 

[PTE800]

piston wash

Not sure of exact comp. but atleast 14:1. I ride from 7400ft. and up, and use premium (91 supposly) All these pics are the Mag side, the PTO side looked the same other than the Locator Pin went and the ring spun/hooked the Exh. port.

I would personally like to have around 13.0 to 13.5 for your application but I know that the aftermarket people like more. More compression does help on throttle response but I'm not sold on it otherwise. Now if you want to blend race fuel that's a different story. Keeping the squish tight is a good thing but running higher compression is not always. Besides, a little lower compression gives you some "fudge" room for borderline gas. I'm not saying that compression is your problem but do keep it in mind...
pm me if you want some details..