89 125hp force outboard WOT problems

[timmons22]

Boat will run fine and everything other than when running WOT for a couple minutes. It will bog way down and eventually die if i dont throttle way down. I go back to check the bulb and more times than not it will be rock hard. Im a long ways form a mechanic so I appreciate the input. Thanks

 

[pnwboat]

Sounds like you have some type of fuel restriction. Did you actually try squeezing the primer bulb when the problem occurs? Might be something as simple as a bad primer bulb. The check valve inside the bulb sometimes stops working like it should. The fuel pump diaphragm is the first thing that comes to mind if it's not the bulb. Make sure the fuel tank vent is open and not plugged. Other possibilities are bad fuel line caused by internal de-lamination causing a restriction, or debris in the tank partially blocking the fuel pick-up tube.

 

[Jiggz]

If there's one thing you need to do first and foremost is to install a clear fuel filter between the fuel pump output and the carb's input. This is a less than $5 mod using the G2 fuel filter from W-mart. The filter comes with the hose clamps already so it is only a matter of cutting the already existing fuel hose and installing the filter.

Then after, test the motor in the water again but this time with the cowling cover off. Watch the clear fuel filter and it should at least stay full or 3/4 full at all times. At WOT and the fuel filter empties, it means there is problem upstream of the filter, i.e. fuel pump, air leaks in the fuel lines, bad primer bulb check valves, closed fuel tank vent or restricted fuel pick up tube.

If the fuel filter stays at least 3/4 full at WOT, then the problem is the carburetors, i.e. improperly set floats, restricted needle ports, binding in the floats, etc.

 

[timmons22]

Update...installed new fuel line, bulb, blew everything out and put fuel filter after the fuel pump.. Went out to run and did notice that running wide open the gas eventually emptied out of the filter then bogge down so it looks like I'm making a little progress. So what's the next step? Rebuild the pump??

 

[timmons22]

another thing I noticed while driving with the cover off that both carburetors spit gas out of side periodically I can't imagine this be normal any help on this please?

 

[Jiggz]

The spitting gas off the carb's sides indicates the carb's needle valve is not closing as it should when the fuel level in the bowl is high enough. Now, I am referring to the carb vent hole which is on the side of the carbs and not the "mouth" of the carb. However, if the spitting is off the mouth that would indicate a bad reed.

The filter emptying indicates a bad fuel pump or leaks from the fuel hoses, restricted tank vent or fuel pick up tube. Before taking things apart, I highly suggest using an external tank and making sure none of the fuel hoses has any air leaks (indicated by bubbles in the clear fuel filter at idle or low speeds) or better yet using a different set of fuel hoses and primer bulb. If the problem goes away, you can tell the original problem is most likely from the hose or the tank vent. But if the problem persists, then you can tell it is the fuel pump that is the source of the problem.

 

[timmons22]

I took apart the fuel pump and found that the two screws that hold the valve in were completely out and the valve was sitting sideways. There was also a real small hole poked through the diaphragm. I ordered a fuel pump kit so I'm hoping this solves my problems. Thanks for all the help so far.

 

[pnwboat]

Inoperative check valve and hole in the diaphragm. Sounds like you're on the right track in resolving your problem.

You can quick test on the fuel pump to verify the check valves are operating properly after the pump is put back together by blowing through the inlet on the pump. You should be able blow through the inlet. Then try blowing through the outlet. You should not be able to blow through the outlet.

 

[Jiggz]

Great! And if that resolves your problem just make sure you post back the conclusion for others to see and for future references.

 

[timmons22]

Got the pump rebuild kit today..rebuilt the fuel pump and took the boat out to the lake and ran excellent. Thanks for everyone's help.

 

[Jiggz]

Congrats and enjoy!