How much loss rpm?

[RICKRICK1]

How much of a loss of RPM will I experience by changing the size not pitch of my prop? Have replaced my 13 1/4 inch 15 pitch prop with a 14 1/2 inch prop 15 pitch.

 

[kenneths]

Re: How much loss rpm?

I'd say in the 300RPM range, but someone else may prove me wrong..............Thats alot more diameter. Some will say it does't matter but I've played with this before.........k

 

[kenneths]

Re: How much loss rpm?

p.s...It's also unusual to find the prop with that much bigger diameter in the same spline configuration anyway......

 

[RICKRICK1]

Re: How much loss rpm?

Kenny The motor is a 67 65hp merc and it is in the same spline and shaft that is on the 75 thru 150 and up. I currently push 5300 rpm with the old prop. The merc book says 4800 to 5300 WOT so hopefully it will not fall below that. got the prop from ebay and wasnt sure as to the diameter as it was not posted. this looks super big on the motor but will try it and see. If not will have to get old prop reworked. I will get back on thursday or friday as it will be at least then before can get too the lake.