F115 not running good

[Freddy1961]

I have a 2005 F115 that is misfiring at 2800-3500 rpm (noticably)and will only run up to 4800 rpm.I have drained the gas and replaced all (3) fuel filters and replaced the spark plugs,the motor currently has 152 hours on it.I was going to replace the spark plug cables but have been told that they do not come out of the coil packs,would there be a way to test the coil pack.When I put the motor in neutral the rpm's will go up and you do not here any misfire?

[boats.net]

Need to run a fuel pressure test to see if loosing fuel pressure to fuel injectors, VST may need to be cleaned.

[Freddy1961]

I cleaned the vst when I replaced the fuel filters but my pressure guage will not connect to the fuel rail pressure fitting

[boats.net]

You would need a peak reading voltmeter to test ignition components, you can check resistence values on coils but need to run CDI output test to coils while running along with timing light to find which cylinder is miss firing to find a miss.

[Freddy1961]

Well after debating the situation I was told by a local boat dealer to have the injectors cleaned sent them to fuel injector man and now the motor is running like new again

[BaileysBoat]

Thank you for updating. Glad to hear you are running well again.

I hope you have a 10 micron water separating fuel filter installed upstream of the motor.