smoke during acceleration or when cold on go kart

[justinkart]

hi
I have a baja reaction 150 go kart that blows a lot of whitish smoke when its cold or when i accelerate.

It had new rings put in and then worked fine. after it sat about a year the thing blew smoke again.

it holds pressure so the rings should be good.

I tried new oil and used a 10w40 thinking thicker is better.

Could this be a dirty carb? any ideas before i try to replace valve guides?
Is there a way to check valve guides?
thanks for the help

[justinkart]

Other then the smoke it runs great and does not burn that much oil but it does smoke alot!!