Fuel Problems/Ignition Problems?

[FlaKeys00]

Hey Guys...purchased boat month or so ago....F225 Yamaha 2003 model with 2010 powerhead. First 5 or 6 trips out boat ran like a top. Would turn up to 5300 in down trim position and would get there pretty quick. Next trip out running good then throttling up got to about 3500 and bogged down as if starving for fuel. It intermittenly did this that trip out. I have since changed water seperator under cowling, the f shaped filter going into VST and r and r filter inside VST tank. Today launched boat and right off turned up to 5000 went back to dock to pick up famaily members and tossed lines and would not turn up over 4500 and seemed to have a miss or vibration. Anyone have a clue? Could it be a coil breaking down or something. Very irritated at this point!

[BaileysBoat]

Bogging down would seem to be fuel related. You might have a plugged injector screen(s) that would also cause lean misfire. How bad were the filters and the VST?

BTW you should have a 10 micron water separating filter installed upstream of the engine.

Must be a story, having a new powerhead and all. Why not do a compression test first? You can read the plugs and test the coils at the same time.

Keep us posted, we feel your pain

[FlaKeys00]

Thanks....The filter in VST tank was pretty plugged...I believe the previous owner must have changed the other two and I do have a spin on water seperator up stream of engine. I am convinced that it is a plugged injector screen or something in that neighborhood.Got to figure out how to get to those. I am comfortable doing this type its just finding my way. Compression checked out good from 155 to around 170 on all cylinders.