94 Merc 90 hp bogging out of hole

[wargle2]

I have a 94, 90 hp, 3-cyl. Mercury. It runs great except that it boggs down accelerating from stop. If the throttle is advanced very slowly it does Ok. If throttle is slamed, the motor dies or if you pull back quick enough, it will catch back up at idle. It idles good and runs good at all speeds once you get past the bog point. I have rebuilt the fuel pump, but was having the problem before. I have replace dthe plugs, fuel line and bulb and run two tanks with Seafoam thru the motor. I have had the boat for two years. The bogging problem started a couple of months after I bought the boat. Any advice would be appreciated. Thanks.

 

[CharlieB]

Re: 94 Merc 90 hp bogging out of hole

Very typical sign of carb idle circuit getting dirty.

Be vary careful when disassembling the carbs for cleaning, BEFORE REMOVING the idle mixture screws, turn them clockwise IN fully but GENTLY, counting the turns (and part turns) until LIGHTLY seated. Remember this setting, you want to reset these to this same setting once finished cleaning.

Once back on the water these screws should be adjusted to best idle speed while in Forward gear, then turned out an additional 1/8 turn to provide additional fuel for acceleration. Any hesitation or bog, then back out another width of the screwdriver slot and retest WOT acceleration. Repeat until perfect.