Force 40hp

stevey08

Cadet
Joined
Jun 8, 2008
Messages
11
My '94 Force 40HP has just started giving me problems. The motor starts up fine . It runs good for about five mins. then it dies and will not start again for a long time. Starts right up again and dies again and will not start for a long time again. In the drive-way with muffs it runs good for at least 15mins. I turned it off. It will start right back up in the drive-way. I can't duplicate the problem without being in the water.

Any help would be great.
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,753
Re: Force 40hp

Welcome to iboats.
Sounds like the classic overheating engine. But.... it could be several things.

Is the water pump working? Is the head too hot to touch?

When on the muffs, the water pressure from the garden hose may be providing enough pressure to cool the engine.

Is the fuel tank vent open?
Is the fuel line bulb going flat?
 

stevey08

Cadet
Joined
Jun 8, 2008
Messages
11
Re: Force 40hp

Water pump is working while it is running in the lake(says the water pressure guage). If I crank on it very long I smell gas. So I believe tank is venting. Should I try running the motor in a garbage can to verify water pump? While running on the muffs, I noticed the bulb wasn't completely full (I was able to squeeze it a little) but didn't change the way it ran on the muffs. While running on the muffs, I looked in the carb. and gave it some gas. I could see it getting more fuel. I don't believe there to be a problem on fuel delivery.

I just looked at the fuel pump diaphram. I didn't see any obvious signs of a hole (too rich to run).

Thanks
 

stevey08

Cadet
Joined
Jun 8, 2008
Messages
11
Re: Force 40hp

Ran it in garbage can. Same as muffs, maybe a little more water "spit" out than on muffs. Still would not die as at the lake and re-started several times very easy. Head is not too hot to touch but is too hot to leave your hand on it for more than 5 or 6 seconds.

Thanks.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,073
Re: Force 40hp

How many hour or years on the present impeller.Drop the l/u and change the impeller.Make sure the old impeller is all there and no pieces are stuck in the tube.I don't know if your in fresh water or salt.If the imp is good then the thermostat might not be functioning and causing it to over heat.Change the impeller and let us know the results. Jerry
 

stevey08

Cadet
Joined
Jun 8, 2008
Messages
11
Re: Force 40hp

Last night I took off the lower unit and removed the impeller. It really looks fine. There was no warn places or voids in the black rubber. I will put a new one in it today along with a kit in the fuel pump.
I talked to my boat mechanic yesterday morning. He seems to think an electrical problem. I don't mind paying him to fix it. But I can replace parts as good as him. I want to understand the problem. There is just not much to this little motor. All of the wiring looks to be in good condition (no bare places or bad connections).
If these new parts don't fix it, I am going to test the stator next.

Any thoughts?
 

stevey08

Cadet
Joined
Jun 8, 2008
Messages
11
Re: Force 40hp

I went ahead and replaced the impeller although the new one didn't look any better than the old one. I then started tracing electrical problems.

Tried to opertate the kill switch with motor running...nothing wouldn't kill it.
Took the cotrols apart and discovered lots of frayed wires and sorry looking splices. The two wires going through the switch were broke loose from the switch and laying down in the wire gutter. It is an aluminum boat (highly conductive). All you have to do to kill the motor is let those two wires touch eachother or something to conduct across i.e. the boat. I repaired all of the wiring and I believe that I have it fixed.
Probably ran good in the drive because the wires were fairly still with the boat on the trailer. Finished putting it all back together last night. Lake test today.
 

Hicktacular

Recruit
Joined
Jun 13, 2008
Messages
5
Re: Force 40hp

Welcome to iboats.
Sounds like the classic overheating engine. But.... it could be several things.

Is the water pump working? Is the head too hot to touch?

When on the muffs, the water pressure from the garden hose may be providing enough pressure to cool the engine.

Is the fuel tank vent open?
Is the fuel line bulb going flat?

Hey man. It sounds like you might could help me. I am new to boats and want to add a water pressure gauge to my 1995 Force 40 horse. there is a plastic plug in the top of the engine. Is that were it would plug up to? I dont trust the enging not haveing a stream coming out the side to see to know that I am not about to burn the engine up. I may be over cautious on that, but that is just me. Any help would be appreciated.
 

stevey08

Cadet
Joined
Jun 8, 2008
Messages
11
Re: Force 40hp

It is fixed. Bad wires at kill switch making contact with hull. Man, hard to track down.

tks guys
 
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