1990 Force 50 - hot pee

[fishnfool93]

Hey guys. New to the forum, but I've definitely read through some posts in the past. I've got a 1990 Force 50 HP (507Y90C) that I picked up last year for $450. Guy I got it from had taken great care of it, regular changes of fluids, impeller etc. I added a telltale to the motor a few months back, and it works GREAT. However, I had the boat out last night and noticed that the telltale water was pretty hot. Didn't have a thermometer on hand, but definitely hot, and much warmer than usual. The stream strength was still good, and I didn't get an overheat alarm or anything after trolling (at idle, or just above) for ~3 hours. Stream temperature stayed hot the whole time, but the motor was running fine.

You guys think that the motor is overheating, or anything needs to be checked/replaced? Figured the impeller is fine because the stream is strong, but maybe the thermostat is gummed up or needs replaced. Thanks in advance for your help!

Robert

 

[Zink357]

Hot is ok. Too hot to hold your hand on it is when you get concerned I believe. If you have an overheat alarm that is confirmed working, then not much to worry about. Others here more knowledgeable than me will be of more help. You can pick up a cheap infrared thermometer on amazon like $15 if you want to be sure.

 

[Nordin]

I agree with Zink357, if you know that the overheat buzzer is working, then no worry.

You can check with a infrared thermometer (gun typ).
When checking, aim close to the plug which is the hottest area.

Check the theromstate that it opens by put it in hot water at the stove.
You can also test to run without the thermostate and see if the telltale water gets cooler.

 

[jerryjerry05]

Key on, ground the orange lead and the buzzer should sound off.
No buzz?? then change it to a motorcycle or car horn, just make sure it's wired right.

The temp gun great addition to any tool box.
The areas to shoot are the sides of the cyl. housing where the cooling passages are
and the head.
Shoot everywhere.
Your thermo should be a 130d so the temps shouldn't be much more than that.

The area right at the plug might be as hot as 200d don't worry as the cooling water jacket
takes care of most of that heat.

If you really want to check the system, remove the thermostat and see if there's any build up??
Usually the lower passages get clogged first and if the thermo has any buildup then removing the head
would probably be a good idea..

The pics were from a pontoon boat that never got flushed after years of use in salt water.
Yet it didn't sound off the alarm.
The lower passages were about 70% blocked.

The heat gun showed it was running hot.
As much as 190d in the lower areas.
It's a wonder the motor didn't burn up???