Oddly had a successful seatrial yesterday. No overheating, seemed to run as it should. Thinking to replace the temp switch with a sending unit to view the temp real time.
Mission failed. New impeller also didnt solve anything. I suspect now a blown head gasket or something worse. Engine will barely start or run. No longer seems cooling system related. the chase goes on, or I am done with this motor.
jgmo you're a genius, sir. thanks. so i shook the gearcase upside down and out came the woodruff key.
Guess now is that I caught a bag (likely in the filthy water i was ripping thru) and i guess impeller ran dry and failure mode was inner housing wearing and woodruff leaving the chat? ill...
good point, I will back flush again with the gearcase off to make sure to key made its way up. also - Q - how do i know this part here is in the right orientation when i re-assemble? i may have moved it from how it came off the motor... https://photos.app.goo.gl/df2n9wQd5MYCYxXW8
Update- took apart the whole cooling system. found two bits of old impeller and the 'new one' the guy put on. guess what
? no woodruff key at all! shaft can freewheel almost inside the impeller. so, new parts on the way. I think this was the smoking gun though!
So i tried a thermostat set for 140F instead of the 160F standard one. Still overheats. I see good flow out the prop exhaust port, but wonder if I am losing too much thru the bypass valve. I pulled the spring out a bit. still seems only way I can get enough flow thru the engine is just to fully...
The interesting thing is, I ran this motor for maybe 20 hours at least before the problem developed. As it is a 1998 motor I’m sure it has many hours on it.
Thanks sir! I tried the pot of water method and found both old and new opened at right temp. So the thermostat doesn’t seem to be my issue . I suspect a piece of old impeller from a previous owner or something else maybe obstructing the water flow.
Hi All,
I have a 1998 Honda BF75a and it overheated the other day after a long fast run.
I found some debris blocking the port leading to the tell tale, but nothing too crazy.
Replaced thermostat, still overheats right away and looks like good flow out the prop / tell tale.
Remove the...