It runs and purrs like a kitten all day. But atleast once per outing I am giving it the throttle and it feels like its running out of gas. It normally starts right back up and then runs great the rest of the day. I cant figure it out. Its a 94 Force by Merc. I know that Force doesnt get much respect here on the TFF but other than the occasional bog down its perfect. Any clues ? Thanks guys !

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[img]http://store3.yimg.com/I/obflag_1769_13099542[/img]
Jimmye4fish

My Force did the same thing, weird huh? I even had it checked out after the first few times it did that--- Scott at Tim's Marine said everything was fine. My Force has now been laid to rest--needs new pistons and have decided I need new boat. Don't freak jimmye4fish, my Force was a 50hp made around the time parachute pants were cool.

Hey Jimmy...did you replace the fuel pump lately? Remember when you got it and I gave you a list of things to do to keep it running? The fuel pump,plugs,decarb and water pump need attention yearly. If your fuel tank vent is open, the bulb is hard, and you are running fresh (precisely mixed) fuel, its probably the pump. Will only get worse if that is what the problem is...May the Force be with you(not me)

Actually I have done the plugs decarb. I was an auto mechanic for 9 years and I dont understand how a fuel pump can work fine for 2-3 hours then one time bog down and die, start right back up and run the rest of the day perfect ? I hear no noise like an electric fuel pump so it must be mechanical. Its weird, really weird. Unlike anything Ive ever seen or heard of. How hard are the fuel pumps to replace ? I plan on doing the water pump soon so I guess I can do the fuel pump while Im already dirty.

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[img]http://store3.yimg.com/I/obflag_1769_13099542[/img]
Jimmye4fish

Mechanical fuel pump...has a little rubberish type diaphram that goes bad. Piece of cake to replace(as is the h2o impeller). Might want to drain or pull float bowl to check for floaty debris getting sucked up into the main jet. This will cause an intermittant problem like you described.PS-you got an inline fuel filter on it right?

I have experienced the same deal with my Merc XR6. However, when its cold or cool outside it runs great. Hot days it runs great at first then bogs down later in the day upon restart. It feels as if we are not getting fuel. most of the time it runs great. Do ya'll think it is the fuel pump as well?

Mike you might check with a dealer but I believe your problem caused a call back on quite a few Mercury's from the 94' to 97' range. If I remember right they were calling that problem Vapor Lock. Said that the gas in the bowl was evaporating while you were fishing and then when you would try to crank it would have to refill the bowl. I could be all wrong as I am working off of memory

Jody

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I guess that may be it. I should clarify that the engine starts ok later in the day. It's after starting when I hit the throttle that the engine bogs down and wants to die if I keep giving it gas. I have a 99 model. I guess the cold weather doesn't allow the gas to evaporate as fast.

I had a 70 hp Nissan. After letting it sit a summer I had problems with it running at WOT. I took the carbs apart and cleaned them throughly. Thought I had it, but still the same problem. Idle good, ran good, then after a few stops it would start acting up. Took it to dealer and they replaced needles and floats, (i think)and she ran perfect. He could tell me anything other than possibly the rubber end of the needles were soft and would stick or the float was saturated and after a while would not keep the fuel at proper level, starving the carbs. Cost $130.00, and worth it. Hope it helps.

It sounds like either of 2 things. It could be your fuel filter is so clogged up that very little fuel is passing through it. It will work ok when the fuel demand isn't high or when you let it sit a while and the pressure equalizes. The other thing it could be is the breather to you gas tank. If that one gets clogged up with water and debris, a vacuum begins to form as the engine sucks fuel out of the tank. At some point the vacuum will become so great that fuel can no longer get to the carbs until the pressure has equalized again. You should pull off the hose from the breather to the tank and blow it out with compressed air. Good luck.

Don't rule out a bad check ball in the primer bulb. Changing the bulb fixed my Evinrude 120.

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steve pine