150 HP Force falling on it's face after about 1 min wide open.........

[brinker232]

I have a 1990 Force 150. It runs great through all spectrums of the throttle range except wide open. After a minute or so it starts cutting out and will eventually drop down to an idle after a minute or so I can nail it again and it's fine. It's almost like its overheating or something but I installed a tell tail so I know it's pumping water. I've pulled and cleaned the carbs. Any ideas or suggestions?

 

[JB]

Re: 150 HP Force falling on it's face after about 1 min wide open.........

Look for a heat failure in the ignition system or a weak fuel pump not able to keep up with fuel usage at WOT.

 

[Frank Acampora]

Re: 150 HP Force falling on it's face after about 1 min wide open.........

It is running out of fuel. That engine uses two fuel pumps in series to supply the three carbs. If either pump is not functioning well, the engine will run out of fuel at full throttle . Then, when you idle it for a short while, the carb bowls will fill and the engine will run like hell for another minute at full throttle then slow again. --ad infinitum.

Remove both fuel pump covers and replace both diaphragms and gaskets. Then check the screens in the black plastic pump covers. Lastly, check any quick-connect fittings for partial clogs. If there is an in-tank strainer or filter, check that for partial restriction also.

 

[pnwboat]

Re: 150 HP Force falling on it's face after about 1 min wide open.........

Like JB suggested +1 on the fuel pumps. Check the fuel pump diaphragms in both of your fuel pumps. Make sure the vent for your fuel tank is not plugged.

 

[Jiggz]

Re: 150 HP Force falling on it's face after about 1 min wide open.........

Might want to install a clear glass fuel filter between the fuel pump discharge to the carbs inlet for troubleshooting purposes. If the fuel filter empties when the engine slows down at WOT it is obviously a problem with the fuel pump and associated hose and tank. To isolate, try using an external fuel tank directly connected to the fuel pump and if problem persists, it is obviously a fuel pump problem. If problem goes away, the problem is with the suction hose and fuel tank.

 

[hbryant123]

Re: 150 HP Force falling on it's face after about 1 min wide open.........

I had a motor do this once, The problem for me was a bad gas fitting, it was sucking air so if u went wot it couldnt pump enough gas for it.

 

[jerryjerry05]

Re: 150 HP Force falling on it's face after about 1 min wide open.........

To rule out overheating???
Test the sending unit,key on ground, out the orange lead on the junction panel.
It should make the overheat buzzer sound off.
But like the others suggest.
A blockage or a bad connector.
The inline Force/Chrysler are junk.
I removed them the first week with my boat.
Profile? Location? In the US were stuck with Ethanol.
If you have to run E then check all the hoses for soft mushy.
It delaminates the inside of the hose and will melt the rubber making it collapse and shut off the fuel.

 

[brinker232]

Re: 150 HP Force falling on it's face after about 1 min wide open.........

Thanks for all the advice. I have pulled the Fuel Filter screens, the first was full of what appearaed to be the inside lining of the fuel hose in pieces. Nothing got past the screen but it was packed. Cleaned it out and still had the same issue. Is it normal for fuel to spray out the front of the carbs at idle? Also, anyone have a diagram of the fuel pumps showing what to remove and a part number for the replacement parts?

 

[brinker232]

Re: 150 HP Force falling on it's face after about 1 min wide open.........

One problem is the inside of my fuel line appears to be stripping away and plugging everything up! New hoses and and electric pump to bypass the mechanical one for a test run. Thanks! I will update my profile soon!!!! Sorry!

 

[brinker232]

Re: 150 HP Force falling on it's face after about 1 min wide open.........

I finally figured out the fuel problem. My "Mercury" fuel line between the Fuel pump and the side of the boat had come apart inside and completely plugged it's self up. $5 in fuel line, 6 clamps, a new See-thru filter and she runs wide open about 40 mph fully loaded with a 19 prop on it. I think I'm going to get a 21 as I do absolutely no pulling of any kind. All we do is ride and park on the beach! Thanks for all the input. So so long of a thread time wise, finally fixed it last weekend and wanted to wrap up this thread with the final fix!!!!

 

[foodfisher]

Re: 150 HP Force falling on it's face after about 1 min wide open.........

Just keep your RPM's controlled.

 

[jerryjerry05]

Re: 150 HP Force falling on it's face after about 1 min wide open.........

5000-5500 is the WOT operating range.
Go for a ride and see what your doing?
Remember too much of a load can affect the results.