what pitch prop

[pfl1p]

hello i have a 20ft 1989 arp pontoon. i just put a 1988 90hp mercury outboard on it has a 19 pitch prop.Everyone i know says to put a 14in 15pitch stiletto star II prop on is this a good ss prop and pitch? sure would like to know if this is right before i spend the money thanks for you input.

 

[steelespike]

Re: what pitch prop

What is the rpm and speed with the 19? A 14 or 15 is probably close.
But don't change without your present specs.

 

[pfl1p]

Re: what pitch prop

my speedo is not working. and the rpms is wrong still working on that. the rpms were tacked out but the motor was not over running so not getting correct reading . i'm guessing it was going about 25mph.

 

[Silvertip]

Re: what pitch prop

And just what does this mean? "the rpms were tached out but the engine was not overrunning". If the tach was pegged, how did you determine the engine was not over "reving". You need to read the sticky titled "READ THIS FIRST" so we have some performance data to work with. As a minimum you need accurate wide open throttle RPM with what you consider an average load. Speed is rather unimportant since once you get the engine running at the upper end of the manufacturers rpm band (through prop selection) speed will be whatever that prop provides.

 

[pfl1p]

Re: what pitch prop

20ft 1989 arp pontoon it has an aluminum prop with 19 pitch. i had 5 people on board which is average for me. Soon as i throttled up 1/2 way i was tached out. So i dont think my tach is correct. Not to worried about speed just want the right prop for the pontoon. I just got a new tach will put it in this weekend to see if that works to get a good rpm reading.thanks i will post it.