running hot

[dc in ms]

I have a 1986 Johnson 9.9 HP J8RCDE / B0105197. The engine ran hot (205 degree f)...no tell-tale...I cut it off. I pulled lower unit and found no key with impeller. Key was installed...lower unit back on...engine fired and ran...a few minutes later I had positive tell-tale water discharge. Now, a few minutes after this the water stream stopped...it appeared that steam / hot air was coming out....it ran hot again (200 degree f) I shut it off. I then removed the thermostat housing and thermostat. Fired it back up and exhaust gases (heavy) were coming out of thermostat .

Ant ideas of what's going on here.

Thanks

 

[itstippy]

Re: running hot

Have you had that motor on that boat for a while with successful water flow? Just verifying that the waterpump sits low enough in the water to prime. A short shaft motor on a longshaft transom won't pump water.
No impeller key? That's odd. Where'd it go do you suppose?

 

[jtexas]

Re: running hot

water pump failed for some other reason and the key fell out unnoticed on disassembly.

install whole water pump kit


(just guessing)

 

[itstippy]

Re: running hot

I haven't seen it before, but I'll bet that if the water tube popped out of the upper grommet you'd get exhaust coming out of the (open) thermostat housing. The exhaust enters the exhaust tower, finds a nice open outlet to escape from (open water tube grommet), and takes the easy way out rather than force its way through to the proper exhaust outlet. Too much slop in your water tube length, or a busted upper water tube grommet, cause the tube to come detached.