my bike seems to be jetted as good as i can get it. the general appearance of all surfaces are perfect chocolate brown. >>>with the exception of the tip of the electrode, which is white. i'm only talking about the tip here - an area the size of a pinhead.
i'm thinking this is a problem for 2 reasons:
1) i've never had a plug look like this
2) I"m getting some kind of pinging at mid throttle in third
gear.
the sound is almost like one of those mexican rattles, but if the rattle only contained 2 or 3 pebbles. not very loud. i know what detonation from not enough octane is, and this isn't it.
some of you will be quick to say that since we are talking about mid throttle its the needle. if that were the case the L shaped arm of the plug should be white or grey. which it is not. the bike is at the line of blubbering so i know i can't go any richer. i was told by a factory mechanic once that this arm is the indicator of the needle, while the fat ceramic insulator that goes up into the plug is the main. i can't remember how to read the pilot from the plug.
the bike in question is a stock '03 cr250. (vforce and pc pipe are the only mods). i run pump 91 octane with klotz octane boost to bump it up around 94. i'm at sea level, and presently jet with 30 pilot, 70 needle in 2nd clip, and 420 main.
the only alternatives i haven't tried are the pilot jet and plug heat range (i'm using a br8eg).
appreciate the input guys!