250 optimax misfire above 4800 rpm only

[dblackstone]

Coming back up the river today I started getting a misfire above 4800 once boat was on plane. No misfires at 4700 rpm or lower. No faults came thru Vessel View Mobile. Temp was normal, charging volts normal.

Will drain vst tomorrow and check fuel and air pressure but pretty sure it is probably a coil or spark issue.

Any other input is appreciated.

 

[dblackstone]

I have double checked coils and alternator, I have only pulled the top 2 plugs and they look good.

I have a new set that I will gap and replace them all and hopefully that solves the problem