Problem Solved…

[steve2manyboats]

PROBLEM SOLVED – Turned out the impeller was weak. Popped in a new impeller and the temps went down a lot. The old impeller was only a year old, but had taken a set. Rear water jacket water temp went down 20 degrees. However, the tell tale stream didn’t change with the new impeller even though the new impeller clearly is delivering more volume. That’s what threw me – stream seemed fine but the motor was not getting enough water volume.

I didn’t have an IR gun the last time I owned a 50 Merc. But that motor never ran hot. The tell tale stream was only warm to the touch and you could hold you hand on the rear water jacket as long as you wanted. On this motor, before the new impeller, you could barely hold you hand in the tell tale stream, even though it was strong, and you could only touch the rear water jacket for a few seconds.

Since this motor seems to need a strong impeller, it’s probably going to get a water pressure gauge like all my V6s do.

Steve2ManyBoats