johnson 50hp overheating

[Jeremy1986]

i pulled the thermostat out and replace with new one and put a new water impellor in the lower unit. i go to start the motor and the motor is pumping water out the mid section but the head is getting to be around 200 degrees. so i took the thermostat back out and took a air chuck to the high pressure valve and the thermostat hole and the air was coming through the mid section. so i put the motor back together without the thermostat and she is still running hot but she is down to 180. any suggestion. i running it in a barrell. thanks for your help. the motor is a 1973.

 

[Jeremy1986]

Re: johnson 50hp overheating

does anyone know how the water travels through the head and the rest of the engine.

 

[Cofe]

Re: johnson 50hp overheating

Make sure that the water level is well above the pump area on the lower unit.

 

[Jeremy1986]

Re: johnson 50hp overheating

i put in the trash can and the water is 1/2 way up the three slots on the hole of the cavatation plate. the water pump through the mid section and when i give it a little gas the water shoot out the barrell. then when it is idling it is just dumping back in the barrel.

 

[Jeremy1986]

Re: johnson 50hp overheating

that on top of the plate

 

[Cofe]

Re: johnson 50hp overheating

Running a outboard in a trash can of water is only good for idle conditions. If you start to rev it up, a bunch of exhaust bubbles get in the water, and limit the amount of water the water pump can pump. This will also make the motor overheat.

 

[cacien]

Re: johnson 50hp overheating

gotta take out the pressure relief valve and and the spring as well to work without a thermostat.

 

[ghiguy]

Re: johnson 50hp overheating

I am a new boater. I also have a 50 hp Johnson outboard, I think it is early 80's, that is overheating. I just had it rebuilt last spring. The water pump was not reworked, so I am guessing that is the problem. I did some research on line on how to remove the lower unit. When I attempted to take it apart, I could not find the connection to detach the shaft. I think there should be a couple of nuts, but could not find them. I purchased a service manual but no help. Can anyone point me in the right direction?


Thanks

Mike

 

[cr2k]

Re: johnson 50hp overheating

When you post your own thread you will find help. It is NOT good etiquette to Hi-Jack someone else's thread.