Reply To: 1972 85 hp V4 overheated…..

[amuller]

This discussion seems rather inconclusive. Will try to run through the sequence of events.

Motor is stock except for addition of cooling water telltale.

Had motor out for the first time since I went through it and ran for about an hour at varying speeds but only momentary full throttle.

(With the fixed idle and main jets there is not a lot to adjust other than the relationship of timer base position to throttle plates….)

Motor ran very well to my way of thinking.

Returned to ramp in 3-4 ft depth (shoaling to 2-3) at around 1500 rpm (no wake area).

Motor began to slow, looked and saw no telltale discharge, advancing throttle did not produce speed increase, motor stopped and we returned to ramp using trolling motor.

A few hours later, pulled plugs, checked compression as reported, ran on muffs with no apparent problems. Pumping normally.

So, do I assume something like the bag scenario and try another run, or dig further into motor first? Drop gearcase? Open thermostat box? Change stat?