I've been struggling with the (to lean to rich) debate. Last night my brother changed his main jet from a 260 to a 250 on his blaster and there was no noticeable change in the color of the plug after doing a full throttle chop. How could this be? He has FMF pipe and silencer, aktive reeds, reed spacer, and K&N filter w/vents in the box. He was getting a little hesitation just of idle and Trenga told him to try the 250 so he did and it helped the hesitation a little but why didn't the plug whiten up on the FT chop? And I to have been playing with my warrior and the plug always seems to be light gray too light tan in color at FT.

 

The main jet wouldn't help the hesitation off idle. Trenga isn't the best place to turn to for jetting. They are a great shop, but I wouldn't trust them.

If there was no noticable change in color, he didn't ride it long enough at full throttle. You can't just bring it up to full throttle and kill it, you need to ride it at full for a while, like 10-20 seconds at least.

 

I usually run my Warrior for at least 10 minutes of good hard riding before checking the plug color. If the Blaster was running fine at 1/2 to full throttle before, put the 260 back in. A hesitation off of idle is a pilot jet. Put a smaller pilot jet in and see how the hesitation is. You might have to drop more than 1 size. The rich, lean debate is easy. If you're asking for horsepower(accelerating) and it breaks up it is running rich, if you're not asking for horsepower(decelerating) and it breaks up it is running lean. If you run either quad on flat ground in 3rd or 4th gear at idle and then without shifting bring it up to the max rpm you can and then let the quad decelerate all the way down to an idle and there is no breaking up of any kind I can guarantee you'll have good spark plug color after riding the quad for 10-15 minutes.