1993 Force 90 over heating problem! plz help

[Kam1310]

Hi there, i currently own a force 90 a 1993 model i am located in New zealand we have owned the boat for around 9 months now, when we purchased the boat the seller told us they just replaced the water pump , plugs and did a complete service. We took the boat out and everything was fine, we took it out about 3 - 4 times, and now it's summer the boat haven't had a start for over 2 months we took the boat to the ocean started the engine everything seemed to be fine but about 10 mins later the Over heating siren started to go off, so we turned everything off and 10 mins later started it again it was running great then 30 mins go past same problem happend, So now i have no idea what is going on water is coming out the top but not as much as it used too. I have been trying to find any instructions on how to remove the thermo and to check if it is rusted or the impeller if it is damaged but can't find anything, If any one can help it would make my day!

Thanks guys

Cam

 

[jasonbailey]

Re: 1993 Force 90 over heating problem! plz help

Check the thermostat. If it is a 3 cylinder, the thermostat housing should be on top of the head, held in with screws. Also, check the compression. My old Chrysler, pre-force, did the same exact thing. The problem was a blown head gasket.

It sounds serious but really was not too bad to fix. New head gasket was about $35.00 (US) and about an hour or so of my time. You will need a torque wrench to reinstall. If memory serves torque settings were 220 inch pounds.

 

[pnwboat]

Re: 1993 Force 90 over heating problem! plz help

Make sure the water intake on the lower unit is free from obstructions. It's not uncommon for seaweed or other debris to clog the intake when cruising in the ocean.

Take the thermostat out and try running it temporarily without it to see if it makes any difference. The motor should have a thermostat to run efficiently, but you can take it out as a test.

I would not assume that just because the previous owner said that the impeller was replaced that it is good. Check the impeller. Might be a wise thing to change it anyway so that you know 100% that it's been done. I've seen many used impellers that looked pretty close to perfect, but were in fact worn out. Very stiff and hard. New ones are much more flexible.

 

[Kam1310]

Re: 1993 Force 90 over heating problem! plz help

Thanks for the info guys, and diagrams to show how to get to the water pump so i can check it? i will look for the thermostat this weekend and take it out and get it in the water and see if it makes a difference, and yes the engine is a 3 cylinder 2 stroke,

 

[wishfish]

Re: 1993 Force 90 over heating problem! plz help

It is possible that the motor was reversed accidentally. What this would do is reverse the impeller causing it to break or be damaged. Knowing that it's been in the saltwater it is likely that you have some corrosion, a brittle impeller. Do two inexpensive things first.

1. Check your impeller, and replace irregardless of its condition (since you're in there, then you know you're good to go)
2. Check your thermostat. Easy: get a candy thermometer and a pot to hold water. Place the pot of water on the stove top along with the thermometer, heat up. Take a piece of thread and "pinch" it in the thermostat valve. Put the thermostat in the hot water and hold by the thread (make the thread long enough you don't burn yourself). When the thermostat heats up enough to let go of the thread you have the temp on the thermometer to tell you how healthy your thermostat is. If it does not release the thread you need a new thermostat.