EHO35 Carbon build-up, what's normal?

[Happy Valley]

Pulled the spark plug to have a look yesterday and the color looks good so then put a spot light into the cylinder. I can see a flaky maybe 1 mm carbon build-up on the top of the piston. This engine has less than 10 hours on it. Is that normal, how clean should a 4 stroke piston top be?

[Mountainman]

HappyV -- no - that doesn't sound very normal for a new 4 stroke
even old ones I have torn down - look fairly clean - little deposit

question comes to mind - how could it build up that fast ?

unless you wish to pull the head and clean at this time

think that I would just ride it - check it again in 10 to 30 hours

I don't know why - but - I think that it will clean itself up

hope that's not wishful thinking

Ride That Thing - Mountainman

[misteright1_99]

I am just guessing here, but when you get a new engine do they run a "break in" oil at first for a certain amount of hours? Are you using a quality oil with the correct weight and rating?