spark plug gapping or too lean?

[mcleod]

my 426ex 11:1 compression is pinking a lil bit at high rpm!

i was wondering if i need to enrich him, or do i need to use a colder spark plug orrrrrrr only close the gap a bit?

im cuyrrently running 168 main jet, and a DPR8Z at .024 !

what is your idea?

slip on
k&n filter
modified air box
450R carb


spark plug look a BIT whity should i go to 170-172 main before trying to play with spark plug?

it's run great till it pink 2-3 time at high rpm operation.

[GPracer2500]

Assuming the sound you're hearing is indeed detonation (aka knocking, pinging, pinking, spark knock, etc) then changing the plug gap won't affect that condition. .024" is the correct gap.

Richening the mixture may help since lean mixtures are more susceptible to deto while richer mixtures are more resistent. If the jetting is correct as-is and it's detonating then a higher octane fuel is really the best solution. But going with a richer than ideal mixture may be an acceptable compromise for dealing with the issue.

I've never personally jetted a 400EX with a 450r carb so I don't know from experience, but many report needing much larger mains then the 168 you're running now. So, it could be that your getting some deto because you're too lean.

[mcleod]

ill burn the actual 92 octane tank and try with 94 after,

gonna raise to a 172 main too. it should solve the problem.

i was only in need to have some advice, im not and expert in quad jetting. im an electronique guy who raise/lower timming/fuel with a portable into the ecu normally :P

thanks!