i took the head off my engine today, and the top of the piston was completly black, should it be? its a brandnew piston only ran about 3 months..

 

yes it can be, it is just carbon deposits from the exhaust side.

 

sounds like you are running a little rich or using a cheaper oil or too much of it. 3 months is a short time for that much carbon buildup.

 

i use yamalube 2-R at 32:1

 

you can run a that oil higher... 40:1, etc.. its all going to depend on your jetting... if the carbon isn't causing detonation your ok and personally i'd rather be safe than sorry especially with a zilla! i'd do a search on zilla's and oil ratio's and jetting just to see what people are running with good results.

I have to refrain from suggesting that you change anything if detonation isn't a problem since i run 250's and not the zilla. I will however tell you i run synthetic 2-stroke from valvoline (convienence of getting it) at 38:1 in the summer and 40:1 in the spring and fall. My pistons uasually go 2 seasons(about 5-6 months per season) before thier entire surface has a coat of carbon. I'm at 700- 1200 ft above sea level and run my jetting slightly slightly rich(almost perfect plug color but i think i can go a tad leaner).

 

how would i go about cleaning out all the carbon buildup? some kind of solvent that will help me wipe it off? i dont want to hurt the piston by trying to scrape it off.

 

if the carbon isn't to hard gasoline works well with some elbow grease.

 

alright, thanks