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1988 johnson 150 hp runs cold

Re: 88 johnson 150 runs cold

You might find there are 2 of them.--------------Somebody likely took them out for some reason. ------------Easy to replace.
 
Re: 88 johnson 150 runs cold

Thermostats at top portion of cylinder heads. Also bypass valves, be aware that there are springs behind the thermostat housing caps.
 
You are taking measurements with a known working instrument, and are you taking the readings at idle on a hose / idle with boat in the water / full throttle with boat in the water ??-------------It all makes a difference.
 
The water temp gauge slowly moves up to 65 this is when I'm in the water at idle , its the same at full throttle and when I have the water hose on it..do you think its the gauge ? or the sending unit....the lake water temp is 68...
 
Gee Joe you take all the fun out of chasing parts that fly!

If they are the original thermostats (which they probably are) I would suggest that they be changed. They just happen to be one of the items I like to stay current with to keep the outboard running right.
 
Agreed..... I just use what is required. A good used part is as good as a new part, why replace it?

The flying thing scenario..... Many years back, outside the shop, I had removed all four bolts from the thermo cover caps of a V6 crossflow, then walked away from it to get a tool I forgot. The service manager, actually just a close friend of the owner with no mechanical experience if you get my drift, walked past the back of that boat with his head in perfect alignment with the thermo caps. One let loose.... WACKO BANGO! Really cracked me up :)
 
Those bolts are standard 1/4x20 bolts. The standard torque for a 1/4" bolt is 5 to 7 foot pounds (60 to 84 inch pounds).

Personally, I just tighten them.
 
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