New V20

[dan4836]

I ran for three hours today at 20 knots and the boat ran great. Logging a temp of about 185. I opened her up but only get 3,500 RPM's and the temp slowly moved past 200. I know these engines are know to heat up quick. I only have the 3" heat exchanger and I know I probably have the wrong size prop as I should be able to get at least 4,300 RPM's.

Will a prop that is too big cause this increase in temp?

Other than that, everything ran great.

I can't read any numbers on the prop...(Mercruiser 470)

[twhrider2]

Welcome to the sight Dan.

Glad to hear you are enjoying your boat. We have similar boats as mine is a '78 w/470 and recently splashed as well and still working out a few bugs. As far as temps I have not saw more than 170 at wot. with a 4" exchanger and new water pump. Still playing with props 21p=3800-17p=4600 now have a 19p to try.
Keep us posted and good luck!!!

[dan4836]

What diameter prop?

I would think a 14 X 19 would work best?