03/YZ450 Jetting for 110 octane.
Posted July 04, 2003 - 10:55 AM
I've noticed some chop at full-throttle and a little backfire during deceleration.
The plug looks clean and dry, whitish brown.
Jetting = all stock, main jet 165, jet needle clip pos 4, pilot air 1 1/2 turns.
Does the backfire indicate rich or lean?
Posted July 04, 2003 - 11:04 PM
You're overkill on the octane and will get no benefit from it. It burns slower which may cause deceleration backfiring, besides being lean on pilot.
Posted July 06, 2003 - 11:33 AM
Posted July 07, 2003 - 04:23 AM
My dealer reccommended race gas for cleanliness, 110 is the only race gas I can find around here.
I installed a 170 main jet and dropped the needle jet clip down to position #5.
The popping and the back-fire is gone. She runs like a raped ape.