Motor Overheated!

[duckhunter55]

Ok im back again with my 25 hp 1978 JOhnson. Finally got motor started. Took to lake to run it. Started up and checked exhaust to see if it was pumping water. Was pumping water, but not as much as i thought it should. Thought it wouldn't be a prob seeing how i was just going to check and make sure motor ran around the ramp. BIG MISTAKE? Was on way back to ramp after about 5 -10 mins and motor cut off. Opened hood, smoke came out. Motor was very hot. Did not attempt to start. Took back to ramp put on trailer. Flywhell still turns over by hand. Seen that around lower cylinder paint was discolored, brown. My Q is, what are proper steps to trying to get motor running again. Last time i had lower uniy off and looked at water pump all looked good. Impeller was not cracked or broke, pump housing looked fine. What would make it not pump water good. Did notice that copper pipe did not fitt to well into rubber grommet. Also when you put impeller into housing should you crush housing down on top, or put in by hand? And laslty are the 2 holes on back of leg housing the only holes water should come out of? Sorry about long post. Any help greatly appreciated! Also how does water get from end of copper pipe to powerhead and back out exhaust?

 

[tashasdaddy]

Re: Motor Overheated!

thru the thermostat. impeller should be changed 2years,

 

[samo_ott]

Re: Motor Overheated!

I'd recheck compression and retorque the head bolts. If that is all good, then concentrate on the cooling issue.

 

[rick_l]

Re: Motor Overheated!

You said it was not pumping as much water as you thought it should. How much was it pumping? Was it a good steady stream. You can have a weak impeller without cracks. When you install a new impeller you slide the housing down onto a greased impeller and turn the rod clockwise and the housing will slip down onto the impeller. You may have blockage which could limit the flow of water. Have you taken the themostat out and started the motor. I have taken the thermostat out before and started it with the cover off the thermostat housing to see if I am getting good flow.

 

[duckhunter55]

Re: Motor Overheated!

I wasn't a stream but more of a heavy mist. Also how do you get to the thermostat? Dou you have to take power head off? Thanks for the help! Also should the copper pipe fit tighttly into rubber grommet or kind of loose?

 

[HighTrim]

Re: Motor Overheated!

The copper water line will be snug into the grommet. That grommet is a trouble area, and very often restricts water flow if you are not careful putting the lower unit back up. I would drop the lower unit and replace the impeller, especially if the age of it is unknown to you. Have a look at the impeller housing for signs of wear. Oil the new impeller blades. Seal everything back up again as per your manual. Before re installing though, remove the t stat, and blow some compressed air up the water line, it should exit where the t stat is, or you have blockage. Also back flush it down the water line, to ensure the passage is clear. Replace the t stat and poppet valve, if your motor has one, with new gasket. Clean out the intake area also before re installing the lu. Follow this link for an exploded view of your motor, it should help you with the t stat , water line, etc... Your t stat is number 19 under "Cylinder and Crankcase".

"http://www.evinrude.com/en-CA/Accessories/Literature/?popup=true"

 

[duckhunter55]

Re: Motor Overheated!

should the copper pipe go up in the quarter sized hole next to drive shaft hole or in the square one that leadss up to two holes where water comes out?