Prop Pitch questions

[karayj]

1989 regal 18.5 Medallion bowrider 3.7LX Merc I think it's the four 470 engine, the serial is 0C520320

Spare prop question. I have a great deal for $40 on a brand-new prop never used and I plan on buying it as a spare but I want to make sure it'll be OK.

Now I do know that depending on the pitch it changes the RPMS what I'm not sure is does it go up or down with the number I currently have a 14.5 19 pitch prop on my boat I'm not sure if that's the right one that came with the boat originally.

I currently have the opportunity to purchase a 14.25 X 21 pitch prop . My understanding it more top end speed and less hole shot which is better. I would rather have top end then hole shot

 

[Rick Stephens]

Higher pitch means more load on the motor for a given RPM. In this case top Wide Open Throttle (WOT) RPMs would drop a couple hundred. It may or may not increase speed, really depends on a bunch of other factors like how your current 19 inch pitch performs, difference in blade design , and how how heavy and how much drag your boat has. As a backup it is probably fine, however, if your current 19 pitch prop is in the range that WOT RPMs are below maximum, then going to a higher pitch will just lug the motor and not increase any performance gains.

 

[QBhoy]

Can often lose top end with more pitch, depending on what you see now, with less pitch. Some hulls like more rpm from the prop to give a little lift.