Motor Bog

[bluefrog]

All,

I'm having engine issues at throttle up (getting on plane) and at full run giving me up and down rev\bog. I got some good advice to change out the main fuel line, filter and primer bulb. Did all this and starts better but the run\bog issue is still there. Let mer try to describe the issues:

1. Bogs down when trying to go full or even half throttle to get on plane.
2. One it gets running it runs great then out of the blue it will start to bog down and stay bogged.
3. It will also run perfect, 5200RPM, 47MPH then the RPM jerks. The motor will jerk down to a bog RPM, 2200 then out of the blue rev's up super quick and then goes back and forth.

It to me seams like a fuel or possible timming\electrical issue. Not sure if I want to fix it myself, afraid of messing things up real bad but would like to get a idea of what could be wrong before I take it to a mechanic.

Running a 1998, Merc. 90HP, 3 carbs std throttle set-up (no hot foot).
Any ideas or thoughts would help for you all.

Thanks,

Dan

[kokid278]

Dan,

Please read my post on the "1995 Johnson V6 Problems". I had similar issues with my engine. I went through everything. Finally, I replaced the coils, plugs, wires, and the power pack. Problem solved!!! Took several months for me to come to this conclusion (I'm a slow poke.....what can I say!!??)But I didn't have to take it to the shop. Probably saved a little bit of money doing it myself, just took awhile to get to the final diagnosis!
Good Luck.........I know exactly what your are going through!!
Greg

[tllewis]

My guess would be power pack. I personally would had rather get an accurate diagnosis, rather than too throw good money after bad guessing. imho.

[koid278]

Tllewis,

Totally with you on that one. I decided to go ahead and hit the major electrical since I have never even touched them since I have owned it(other than the plugs that is!)

Saving bucks is important these days!!

Greg

[Mike Bucca]

Oct 18, 2010 22:39:12 GMT -1 bluefrog said:

All,

I'm having engine issues at throttle up (getting on plane) and at full run giving me up and down rev\bog. I got some good advice to change out the main fuel line, filter and primer bulb. Did all this and starts better but the run\bog issue is still there. Let mer try to describe the issues:

1. Bogs down when trying to go full or even half throttle to get on plane.
2. One it gets running it runs great then out of the blue it will start to bog down and stay bogged.
3. It will also run perfect, 5200RPM, 47MPH then the RPM jerks. The motor will jerk down to a bog RPM, 2200 then out of the blue rev's up super quick and then goes back and forth.

It to me seams like a fuel or possible timming\electrical issue. Not sure if I want to fix it myself, afraid of messing things up real bad but would like to get a idea of what could be wrong before I take it to a mechanic.

Running a 1998, Merc. 90HP, 3 carbs std throttle set-up (no hot foot).
Any ideas or thoughts would help for you all.

Thanks,

Dan

I can't speak to a 98 90HP but the Pro XS 225's have a coil issue problem and what you described above is about what my boat was doing when I had the coil issue. Take what I say with a grain of salt I know nothing about engines.

[bruce482vs]

I heard E 10 fuel does strange things to carb engines.

[bluefrog]

Thanks guys for all the advise. I'm going to try a fresh tank of gas with some Cleaner\Treatment go out and troll for stripers to get good run time at itle and see if that makes any differance. If that doesnt do it I may just spring for a diagnostics at Dalton, they quoted me $90.00 to tell me what is wrong. I could do more damage than that tinkering myself with the motor.

Thanks all again.

Dan