1996 Johnson, 50hp overheating, unknown cause, assistance needed.

The whole story. I purchased a lowe pontoon with this motor, put it in the water the first time and did not realize that the water pump was out (didn't know anything about boat motors at the time). The engine overheated of course. We had the pump and heat sensors replaced. Currently I get good flow from the pee line and the boat will idle and move off the trailer and to the dock. However, once on board and under way, after about three minutes the hot alarm sounds. I can shut down, let it cool off and then go back toward the dock, about three minutes, and sure enough I will get it again. Still appears to have good water flow. I have been told that it could be the VRO isn't working correctly and I intend to bypass that if I can figure out how, to test that theory. Any other ideas or thoughts on what could be the cause of the problem?

Thanks,

CDBird

Re: 1996 Johnson, 50hp overheating, unknown cause, assistance needed.

You can just premix your fuel temporarily. No need to mess with the vro till you test with premix.
If the vro is working it will still run fine with the premix, just a little smokey.
There is a thermostat on the motor.Is this in saltwater,or was it used in salt water?
Salt water causes a lot of corrosion and blockage.
The strong telltale just indicates the pump is working. Circulation could be poor do to the thermostat not working
a or the previously mentioned salt corrosion.

Re: 1996 Johnson, 50hp overheating, unknown cause, assistance needed.

It has been in fresh water only. I will do the pre-mix and give it a shot, see what happens. Is there a way to test the thermostat or is that something I could just replace? Thanks!

Re: 1996 Johnson, 50hp overheating, unknown cause, assistance needed.

You can put the thermostat in a pan of water and heat it check the temp.
Don't know what temp; but should open around 160 or 180.Someone may be along with more detailed info.
Check the water intake is clear.

Re: 1996 Johnson, 50hp overheating, unknown cause, assistance needed.

I will check that out as well and see if I can find the exact temp and check out the thermostat, make sure it's functioning right.

Thanks.