07 250 pro xs 1B550078
Kinda long. Up for suggestions. I have a friends 07 250 pro xs that while running it surges. Comes outta the hole fine but if you level off the rpms, itll start surging. Hammer down on it, itll pick up to 53-5500 then surge to 57-5800, then hold back again. Heres everything ive done and checked. No codes shows up on computer.
New spark plugs, ngk-izfr6j gapped to .042
All coils were replaced in 2010
New fuel/water separator
Comp on all 6 is 120
Fuel pressure is 108
Air pressure is 96
Good spark
Run 93 ethanol free
Checked tuner gasket for leaks.
The burn on the plugs has me puzzled. 2&4 looked normal, good tan color, while the rest looked clean. Plugs have maybe 4-5 hrs on them. Im stumped. Heres some pics of the plugs. Any suggestions?