made it to 10 hour break in after my rebuild.1989 90 hp johnson

johnson89

Petty Officer 1st Class
Joined
Apr 4, 2010
Messages
244
motor is running excellent....118-122 comp. on all cyl.....temp. at idle is 124-129.....seems to run a little cool at idle,above fast idle it is 88-95....slowly going back to 50-1 on oil....had motor up to 5400 rpm...2 people, 15 gal. gas..boat fully loaded for fishing....16ft bassboat.....is there anything else I should keep and eye on.got lots of help from forum during my rebuild
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
The engine will run it's warmest temps when idling in summer warm lakewater. 143-155 degrees. Cooler on the garden hose. Once you crack the throttle, or get the engine up on plane, the pressure relief valves will open in the thermostat housing-flooding the powerhead with extra cooling water. Not unusual for the temps to go down 20 degrees when up on plane or at high idle.
 
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