o-heat alarm, and shuts off in hot weather-01 40hp 4stroke efi

I am having and on going issue with my engine sounding an alarm and shutting off while running. yesterday morning, we were fishing the middle of the lower Potomac, overcast, hardly a breeze (or fish for that matter) we decided to make a run up river to another spot about 20 minutes to get there no problem. fished off the electric motor for about 2 hours, and then headed back to where we started. by now, the air temperature and humidity was up to the low to mid 80's, we ran just off full throttle for about 25 minutes, when the overheat alarm sounded and the engine shut-off, plenty of water coming out of the pee hole no debris on the lower unit. shut it off and restarted ok and idled ok, try'd some throttle and it started missing and shut-off. pulled the cowl off, waited about 10 minutes, started up fine and went to another spot, about a 10 minute run,-cowl-off and closer to the ramp. fished on the electric motor for another hour, it started to rain, put the cowl on, rain stopped, ran to the boat ramp and drove it onto the trailer no problem?? any I-deers?

Re: o-heat alarm, and shuts off in hot weather-01 40hp 4stroke efi

I feel this related to high ambient outside temps, seems fine in the am, when it is still cool out?


thanks

:thumb:

Re: o-heat alarm, and shuts off in hot weather-01 40hp 4stroke efi

Doubt it is ambient temperature related. You might want to rent or borrow an Infra-red heat gun and then check engine temperature if the issue pops up again. If there is a bad temperature sensor it may trigger an overheat when there is none. On the other hand, there may indeed be an overheat condition and continuing to run the engine can cause damage. Oil level proper?? Engines overheat at WOT when the thermostat sticks shut and/or the bypass valve sticks shut.

Re: o-heat alarm, and shuts off in hot weather-01 40hp 4stroke efi

Silvertip said:

Doubt it is ambient temperature related. You might want to rent or borrow an Infra-red heat gun and then check engine temperature if the issue pops up again. If there is a bad temperature sensor it may trigger an overheat when there is none. On the other hand, there may indeed be an overheat condition and continuing to run the engine can cause damage. Oil level proper?? Engines overheat at WOT when the thermostat sticks shut and/or the bypass valve sticks shut.

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thanks for the reply, oil level is perfect, and the oil is clean, interesting comment on the t-stat, when I flush the engine with the garden hose, and say I let it run for 10 minutes or more, shouldn't the water temp be warmer, coming out of the pee-hole?

Re: o-heat alarm, and shuts off in hot weather-01 40hp 4stroke efi

impeller replaced? check. thermostat replaced? check. temp sensor replaced? check. still goes into overheat mode if and when, I am running with the engine cover/cowl on, remove it and place it in the bottom of boat, engine runs fine.??

Re: o-heat alarm, and shuts off in hot weather-01 40hp 4stroke efi

hummmm, that's what I thought, no clues, WAGS (wild *** guesses...sorry) or responses? I thought for sure, that the no cowl = cool engine, would pique someone's interest??