Spark Plug Related: BR9ES or BR10ES?
 

Hi everyone. I have a 50cc (2 stroke) that has been fully de-restricted (Apart from rev limiter in CDI). It has an after-market exhaust system, snorkel removed from airbox, carburettor plate removed (limits air flow), de-restricted manifold rubber, performance race reeds, sprockets changed, and then re-jetted.

After researching online, I found that many people swap plugs to a cooler one after the de-restriction process. I believe the higher the plug number, the cooler the plug right? So I was just wondering, would I need to change my plug from the original BR9ES to a BR10ES or not? Thank You.

you're right about the higher the number the colder.my 2 stroke came with a 7 and mine doesn't have restrictions.

NGK is the only brand that the higher the number, the colder the plug...all the other brands are the higher the number the hotter the plug.