90 HP Force motor help!!

[lindseysmith]

My husband and I purchased a used 1989 Glasport boat with a 90 HP Force motor on it. We are thinking it is the original motor on the boat. Before we bought, we had the guy that owned it take us out and show us that it ran in the water. He didn't want to take it off the trailer because it has no trim motor and he didn't want to bottom the motor out (was shallow where he put it in at), but it started and ran and sounded great. We bought it, and took it out the next weekend, and started it at the top of the ramp, and it cranked fine. As soon as we dropped it in the water, in wouldn't even crank over. Found the solution to that, there was a wire grounding out in the water. Fixed that, then put it back in the water, and it wouldn't run over 1000 RPM's....and every know and then the boat would just quit...we would prime it, and it would start back....but just long enough for us to get it back to the dock and on trailer. We are ready to winterize the boat now, but wanted to try and figure out what was wrong with first. We changed the spark plugs, put good clean fuel in it, and hooked a water hose to it, and it started and ran great. But now we're not for sure if it's sucking water or not...so we didn't want to run it long, afraid we would burn something up. It wasn't spraying water from the top like it does when it's in the water? Is it supposed to do this when you just have a hose hooked to it? Does anyone know where exactly the water flush vent is on this type of motor? Any suggestions as to why it wants to run out of water, but not in the water? Sorry for the long story, just trying to get some answers...wondering if it's even worth the time....

 

[Barnacle_Bill]

Re: 90 HP Force motor help!!

When you say you started it at the top of the ramp, are you saying that you are running the motor out of the water with no muffs attached?

 

[trunctj]

Re: 90 HP Force motor help!!

Lindsey,
It wouldn't be surprising if your old 90 HP Force needs a new water impeller (to pump water up from the muffs into the engine). I had a 1993 90HP Force and had to replace the impeller twice. It's especially likely if you ever sucked up any sand/silt.

You should see water coming out of the top discharge holes when running the engine with a garden hose. With the muffs in place, turn you hose volume up pretty high. Start the engine. Water should come out within a minute. My engine had a high temp alarm (your's might as well), to alert you if you are not getting sufficient water up into the block.

Tom

 

[moparman]

Re: 90 HP Force motor help!!

I'm with Bhile, I hope your not running it out of the water without a water supply,as the impeller won't handle that[water is it's only lubrication while running]. It doesn't take long to burn up the impeller so be careful about running it with no water supply. As far as not running right, you need to check you fuel system [i.e. fuel pump and valves,carbs might be stopped up, fuel lines,ect],it sounds like your having a starvation issue. My two cents worth. MOPARMAN .......ROLL TIDE

 

[lindseysmith]

Re: 90 HP Force motor help!!

What i meant was that it would crank at the top of the ramp we never actually turned the motor over until it was in the water. Then this weekend we put the muffs and a hose on it while we tried to figure out what was wrong with it. We replaced the fuel line from the tank all the way to the filter and added a new prime pump. Put new fuel and oil in the tank after draining it and cleaned out the filter. Then it started fine and ran well all the way to full throttle and sounded very good. But the water wasn't pumping all the way to the jets at the top of the motor so I only let it run for about thirty seconds just to see that it was running better. It may be that the impeller isn't working now, when I first took it to the lake it was shooting water about twenty feet though. But with the muffs I cant get it to run all the way through to the top of the motor. It doesn't have a high temp alarm so I'm trying to b careful about running it too long. I'm gonna take it to the river this weekend to see what it does and see if the impeller is still working.I'm hoping that it was just a fuel issue between the tank and the carbs because that's how it was acting. Thanks for the posts!

 

[moparman]

Re: 90 HP Force motor help!!

The reliefs on the back work when the foot is covered with water, and the motor doesn't make enough exhaust pressure to force it out around the prop while it's under water.It makes it easeir to come out the back at idle this way, once you get some speed up,then the exhaust pressure and void behind then prop allow it to come out there. MOPARMAN ROLL TIDE