Force 85HP Impeller question

[Mike Baker]

I had problems this fall with engine overheating (warning horn activated) while idling. I just took the lower unit off to check the impeller. All the legs on the impeller looked good, bent and engaging sides of housing, except for one which was worn about half way. I will be replacing it but I have a few questions about this.
1) Is one partial leg enough to radically effect the flow of water through the system?
2) Where did the missing piece of that leg go? Could it have ended up somewhere else in the system causing a blockage?
3) Impeller housing,plate and gaskets look good...should I order kit and replace all?
4) Might the problem be the thermostat?
5) Is there any other maintenance I can do while I've got the lower unit off?

Thank you!

 

[jerryjerry05]

Re: Force 85HP Impeller question

Profile,location?
Pictures??Check the tube to tthe motor for the broken piece.
Missing part and block could be a problem.
If the wear isin't too bad re-use the parts.
My pumps are about 25 years old.
the impeller is 1
Check the thermo. Dunk it in boiling water.
Change the oil.

 

[Mike Baker]

Re: Force 85HP Impeller question

Profile,location?
Pictures??Check the tube to tthe motor for the broken piece.
Missing part and block could be a problem.
If the wear isin't too bad re-use the parts.
My pumps are about 25 years old.
the impeller is 1
Check the thermo. Dunk it in boiling water.
Change the oil.

Jerry, I'm in Ohio. The overheating problem started in early summer. I got into some shallow mud/weeds up in Michigan and later that same day I got my first overheat warning. I thought problem went away but again happened on two occasions at a local lake near the end of the season. Only happens if I'm at slow spees/or idling.

This is the first time I've ever dropped a lower unit so I don't know much about them. How to I check the "tube". Can I visually inspect it or do I need to run a wire or something through it.

Is the thermo the thing near the back of the engine (spark plug area) with the red wire coming out of it? What does boiling it do?

Thanks a bunch for your help Jerry!

 

[jerryjerry05]

Re: Force 85HP Impeller question

The wire thingy!!! It's the sensor.That don't dunk.
Tube is the copper tube from the pump to the head.
The top of the head above the plugs is a rectangular box. Inside,that's the thermostat.
While the thermo's out and the lower is off. Back flush from the thermo housing through the copper tube.That runs from the block to the pump.
Try a vacum on the copper tube,try sucking anything from that.

Pictures of the parts?
If the impeller is ok and it still overheats, Then the port exhaust cover might need to come off.
The screws that hold that cover are VERY tricky. They will strip/break just looking at them.So ask for directions if your gonna do that.

 

[foodfisher]

Re: Force 85HP Impeller question

Boiling activates the thermostat so you can "see" if it works or not.

 

[4runneradam]

Re: Force 85HP Impeller question

I removed my thermostat completely a few years ago and no problems since.

 

[Mike Baker]

Re: Force 85HP Impeller question

I removed my thermostat completely a few years ago and no problems since.

.....You might want to read this thread http://forums.iboats.com/johnson-evinrude-outboards/can-outboard-run-without-thermostat-110964.html

 

[Mike Baker]

Re: Force 85HP Impeller question

I've checked the t-stat and it actuates at around 140 degrees. I haven't had a chance yet to flush/back flush the engine from the T-Stat thru the tube. I am hoping that when I do that broken piece of impeller shows up. Is it possible for that piece to have passed through the system or disintegrated?

Thank you to all of you who have helped so far. I'm a rookie at this but learning a lot with your help!

 

[jerryjerry05]

Re: Force 85HP Impeller question

Yup it's possible the piece went away.
Don't remove the thermo it's there for a reason.
Your motor runs best at a certain temp.