prop size

[jimbo_jwc]

Prop results after acquiring 3 different one's over last winter and using on 1987 40hr 3.0 L MCM Mercruiser w/rebuilt original lower unit on 19'6 ' Cuddy Cabin boat .
Original Prop Mercury 3 blade 14.5 x 17 WOT lightly loaded 5000+ rpm
Mercury Prop 3 blade 14.5 x 19 WOT medium loaded 4200 rpm 36mph GPS
Solas? Prop 4 blade 14.25 x 18 WOT lightly loaded 5000+ lightly loaded
Mercury SS vented Prop 3 blade 14 x 19 heavily loaded 4600 rpm 39 mph GPS Is what my boat likes best .
Motor has had new plugs ,fuel pump,points ,carb rebuilt,gimble brg and motor temp at 145-150 running hard WOT over an hour .

Different brand of props and sizes is hit n miss because of blade size's profiles and boats characteristics .

 

[Bondo]

Were talking over a thousand rpm then it should have. IMO that's an engine problem no matter which way you look at it

Ayuh,.... I agree,... without knowin' it's history, the drive may have been swapped to the wrong gear ratio is where I'm headin',....

We need Crownie to verify some of the things mentioned,....

 

[jimbo_jwc]

All 3.0 L lower units 1-1.98 ? I think I saw it stamped in mine .