I know rich is a journeyman auto mechanic so i know he knows way more about what im about to touch on, but here goes...

When i was in school to be an auto mechanic,we were taught build up like that was seen in in buicks/cadilliacs ect... (any cars thats never really driven hard)

Thats carbon build up... A by-product of combustion... We were taught it occured due to the the engine never really reaching operating tempatures (old person style driving) or to rich mixtures... (Or both)


In 1:1 cars build up could actully change the compression ratio of the car and cause knocking. It had to be bead blasted off with a walnut shell agragate (sp?)

Thast why to me, it looks rich. I know im comparing a mini 2 stroke to a large 4 cycle... But all they both really are is air pumps.... So the prinicpals are the same..

Just my .02 not tryin to be a jerk