Force won't stay at WOT

[TheFormerlives]

I've got a 1989 Force 50hp outboard. This past summer while driving it I ran into a couple problems. It gets up on plane fine, and accelerates good, but occasionally after 2 or 3 minutes on plane at full throttle it will suddenly bog down and slow to a little more than idle and it won't get back to full throttle. Any possible causes for this? It only does this occasionally. I've noticed that if I shut off the engine and restart it then I can get back to full throttle. Thanks much.

(New to the forums- sorry if there is already a thread for this)

 

[foodfisher]

Re: Force won't stay at WOT

Sounds like fuel starvation. Plugged or unopened fuel tank vent, plugged fuel filter, faulty primer bulb, debris plugging fuel pickup tube in tank.

 

[TheFormerlives]

Re: Force won't stay at WOT

That was my initial thought on it as well. One thing I've noticed is that often times the primer bulb doesn't have much pressure to it. I'll pump it and pump it and it still won't get hard. Could that be causing the engine to bog down. If so then what would prevent the primer pulb from getting hard...clogged line possibly?

 

[trendsetter240]

Re: Force won't stay at WOT

That was my initial thought on it as well. One thing I've noticed is that often times the primer bulb doesn't have much pressure to it. I'll pump it and pump it and it still won't get hard. Could that be causing the engine to bog down. If so then what would prevent the primer pulb from getting hard...clogged line possibly?

Sure. The primer bulb could be faulty. Try replacing the fuel line and primer bulb and see if that helps. Another issue could be the fuel pump. If you pump the bulb when the engine bogs down and it picks up speed then fuel pump could be the cause. Also check that the vent is fully open on the gas tank.

Try replacing the fuel line first, it's much cheaper. While you are at it replace the inline fuel filter for the engine. It's another cheap maintenance item that you should do anyway.

 

[foodfisher]

Re: Force won't stay at WOT

Primer bulb will only get hard when there is no outlet for the pressure. Closed needle valve in the carb on one end and a closed flapper valve on the inlet side of the primer bulb. Your original symptoms still sound like a vacuum buildup prior to the bulb. A good indication would be a collapsed bulb prior to the motor dying. If so it's a pickup or vent problem. Maybe a kinked vent hose. Are you running a portable tank or under deck tank?

 

[TheFormerlives]

Re: Force won't stay at WOT

The tank is under the deck. I'm about 30 miles from my boat so I can't check any of this right now, but I will be home tomorrow and hopefully be able to take a look at it.

Thanks for all the replies. I figured it was something with the fuel system but I thought I would check with the experts to see if it could be something more serious.