Prop selection

[fastimz]

I have a 1989 Marcruiser 350 with Alpha One. The boat is a 21' Larson mini cab and bow rider. I tested the new engine and the rpm's are way too high. I can hit it and WOT was never found or was at the end of the tach. I was running about 5800-6000 when I lifted. The prop is an Aluminum 21P. I'm going with a Stainless but should I use a 23 or a 25. How much will each drop the rpms? Thanks for the help.

 

[tommays]

Re: Prop selection

i would check the tack against a shop tack first <br /><br />what hp is the motor its hard to believe it could rev that high i would get scared at anything over 4800 rpm<br /><br />tommays

 

[walleyehed]

Re: Prop selection

"Usually" around 200RPM per inch..<br />We run 350's 5500 alot here, but I would shoot for 5200 with just you and minumum load.

 

[fastimz]

Re: Prop selection

THX, It has 330-350hp and The tach has been checked and she is turning that high.