Force 9.9 outboard overheating

[simon]

I have a Force 9.9 2stroke outboard. I was using it the other day when it started to overheat quite badly (quite a bit of smoke was coming out of the top). I removed the thermostat from where the water comes out, but there was still no water circulating. I found a screw marked "vent" just above the prop. When I took that screw out the water started shooting out of the output again. This enabled me to get back to my mooring, which was about three hours cruising time away. during that time the engine faltered a few times and stalled when I put ran it at low revs, or tried to put it into reverse. Have I damaged it by running it with the 'vent' screw out, and what action should I take? (as you can probably tell I have VERY limited technical or mechanical knowledge so if there is a simple way to explain I would be grateful)

 

[aban_esox]

Re: Force 9.9 outboard overheating

Hey Simon;<br />Your original problem with overheating was most likely an impellar problbem which should be replaced every 2 years depending on you enviorment. By removing that vent plug you allowed water to invade your lower unit gear lube and by running it for 3 hours it would be hard to estimate what type of damage could have occured. Sorry.

 

[Fouled Plug]

Re: Force 9.9 outboard overheating

Check compression on both cylinders to rule out a (probably) blown head gasket as a result of overheating. If compression is OK and bore condition looks good (no scuffing) replace the impeller and thermostat. Replace lower unit lube, looking for metal shavings in the old stuff. Replace both gaskets on vent/fill screws. The only good news is the motor didn't get hot enough to sieze, so you have some hope left for it!