Re: '87 Johnson 70 Temp Question
Your gun should read 143-150 when warm, idling in summer lakewater. Not unusual to run somewhat cooler this time of year.The head, exh cover, or block should give you an ideas what the temps are. Likely will run cooler when on plane, as the water pressure increases and the water flow goes up. As a base of reference, the overheat alarm will probably go off at 212, then silence around 175.
