Alarm Sounding problem on Force

[Llunker]

Ok guys, BTW--it is a 1997 force 120hp motor

New Problem. As of a few months ago i replaced the water impeller, thermostat and gave the engine a tune-up with new plugs and everything.

the Boat usually has had no problems but i have only had it out about three times since all this took place.

Today I go out and a buddy of mine and I decide we want to troll the big motor instead of using the regular trolling motor to fish for Stripers today.

All was going well until i hear the alarm sound for an over heat on the motor? Strange --i said. As soon as I heard it I shut it off thinking i didnt want to cause any damage to the motor. We waited the alotted amount of time for this to cool down and restarted the motor and ran around the lake at full throttle no problems.

Again we go back to trolling at slow speeds and again we hear the alarm sound for over heat--this time i look back to make sure the motor's pee hole is exausting water and it is running just fine and peeing ????? weird?????

Again i shut it down and we wait. Again we make another run around the lake wide open with no problems and go back to trolling and this time we are able to troll the rest of the day with no problems???? really weird now--no more alarm ????

Can someone explain what is going on--i called my mechanic and he seems to think it might be a sensor going bad maybe??? or that there may be corrosion somwhere in the tube?

Could I have a faulty Brand new Thermostat--my mechanic said with almost 90% accuracy he doubts it would be a new thermostat that went bad --it just doesn't happen on those items


HELP me figure this out please

 

[pnwboat]

Re: Alarm Sounding problem on Force

Sometimes when an impeller goes bad, pieces of the rubber fins get pushed into the block and water passages. Same thing happens when running in real shallow water where mud and sand get sucked up. You may be able to back flush with a hose by taking the thermostat out and putting the hose in the thermostat cavity. Seal the opening around the hose with some rags to get maximum pressure. You also may have to take of the lower unit to flush any junk out of the block and water tube so it doesn't get pushed back into the block when you fire it up again. Put a bucket under the lower unit when you back flush so you can catch and see what comes out.

 

[Llunker]

Re: Alarm Sounding problem on Force

Sometimes when an impeller goes bad, pieces of the rubber fins get pushed into the block and water passages. Same thing happens when running in real shallow water where mud and sand get sucked up. You may be able to back flush with a hose by taking the thermostat out and putting the hose in the thermostat cavity. Seal the opening around the hose with some rags to get maximum pressure. You also may have to take of the lower unit to flush any junk out of the block and water tube so it doesn't get pushed back into the block when you fire it up again. Put a bucket under the lower unit when you back flush so you can catch and see what comes out.

Wow i never even thought about that--most of the day yesterday we spent it in shallow water 1-3 ft. I never even thought of that.

So should I just try the flush first without dropping the lower unit or would it be better to go ahead and drop the lower unit.

Or did the last three hours of running in deeper water clear the problem???


Appreciate your help

 

[pnwboat]

Re: Alarm Sounding problem on Force

When running in shallow water, sometimes the weeds will temporarily block the water intakes causing it to overheat.

If it's convenient, first verify that the motor is still continuing to over-heat in weed free deeper water. You may not have a problem. From what you stated about the last three hours of trolling with no problem, I'll bet it was just weeds blocking water intake ports.

If it's OK, you should be good to go. If inconvenient, or you do verify that it's still overheating, I would drop the lower unit and back flush with a bucket or large kitchen sieve under the water tube to catch anything.

 

[Llunker]

Re: Alarm Sounding problem on Force

When running in shallow water, sometimes the weeds will temporarily block the water intakes causing it to overheat.

If it's convenient, first verify that the motor is still continuing to over-heat in weed free deeper water. You may not have a problem. From what you stated about the last three hours of trolling with no problem, I'll bet it was just weeds blocking water intake ports.

If it's OK, you should be good to go. If inconvenient, or you do verify that it's still overheating, I would drop the lower unit and back flush with a bucket or large kitchen sieve under the water tube to catch anything.

I did notice after the second time that the peehole was working and I actually took the cowl off while running and it was hot but not boiling hot. Your suppose to be able to touch the thermostat area or the block for 3 seconds and that is what it is suppose to run at.

It was fine and the engine was running at the proper temp.

I think your right--it was weeds,sand and mud...

thanks for the help if it continues i will blow out from the thermostat area.

Thanks