In testing a 1990 Johnson 115 that I bought recently, I ran the engine three minutes or so at idle with a Temperature Gun Infrared Thermometer W/Laser Sight and got 183 degrees maximum on port side and 104 on the port. I decided to replace the thermostat, and went at today in the evening and am trying to use the method used in this Youtube Johnson Overheat repairs Final - YouTube, at the 2:13 mark, Steps to Replace Thermostats . However, my engine is different, the lower aluminum cover of the engine does not move. I can only remove the plastic rear cover over the thermostat cover. Playing around with different tools I was able to get the middle thermostat housing screw but the other two I don't think will have enough room to come out. I already left one 7/16 combination wrench behind the screw when I pulled it out as far as possible and used the wrench from the backside till it would not grab, then used another from the front.
I'll see how far I can go. Either I remove the power head to be able to work comfortable, or maybe drill some holes in the lower aluminum cover to reach all three screws, and plug them up later with a rubber covers. The holes will have to be big enough to fit a 1/4 socket wrench set extension and the 7/16 socket.
Any advice?
I'll see how far I can go. Either I remove the power head to be able to work comfortable, or maybe drill some holes in the lower aluminum cover to reach all three screws, and plug them up later with a rubber covers. The holes will have to be big enough to fit a 1/4 socket wrench set extension and the 7/16 socket.
Any advice?
Last edited: