Force 75hp Lost Power at WOT

[httc10]

I have a 1996 Force 75hp on a 24' pontoon. I have had the boat for 2 years and has been serviced. I have used the boat quite often this summer. Yesterday, took the boat, all appeared to be running fine at 5000 to 5500 rpms. We were about 1/2 from the dock when, all of a sudden the engine reved to high RPMs and then we lost speed. I put the boat in nuetral and then tried moving forward, the boat would move forward as always, then when it hit about 4500 RPM it would rev to high RPM and it felt like the prop was spinning but not going anywhere. I shut the motor off and looked at the porp. It appears to be ok, not sure what to look at. I then started the motor up to head back to the dock. The boat started fine, went into gear fine but would not go above 4000 RPM. Need some help to advise where I should start looking.

 

[1983rinker]

Re: Force 75hp Lost Power at WOT

check all the fuel lines and filters.

 

[1983rinker]

Re: Force 75hp Lost Power at WOT

it sounds like it not getting more gas when you give it more, and it looking for more.

 

[Frank Acampora]

Re: Force 75hp Lost Power at WOT

That sounds like the rubber hub in the prop is starting to spin. It will get worse with continued use until the engine will slip at anything above idle. Remove the prop and mark the aluminum and the bronze insert then replace it and run the engine. If the marks have moved relative to each other, then the prop is "spun" Send it to a repair shop to have a new hub installed. Meanwhile, buy another used prop. You can always use an extra for emergencies.

 

[pipestone guy]

Re: Force 75hp Lost Power at WOT

Sounds like a spun prop hub to me. Try a diff prop. If it works correctly take the old one and have a new hub put in. Shouldnt be that expensive.

 

[john from md]

Re: Force 75hp Lost Power at WOT

+1 on the spun prop. Do a google search as there are a number of places around that re hub props. You can even buy the tools to do it yourself if you are so inclind.

 

[httc10]

Re: Force 75hp Lost Power at WOT

Thanks everyone for the advise. I do have another prop that I can try. I am going to be out of town for several days, so I will try replacing the prop when I get back in town.