Looking for right prop size and pitch HELP

[Tow Joe]

I own a 1977 Glassmaster 18 ft. bowrider with a 140 hp i/o. It currently has a 15x17p prop on it. The boat planes out quickly but has a very low top speed, about 30 mph at 4400 rpm which is within max operating range according to the owners manual. What size prop would I use to get a little more speed out of my boat? Any suggestions would be helpful as I am new to boat ownership.

 

[junior1113]

Re: Looking for right prop size and pitch HELP

is that 15x17 alluminum or ss prop??

 

[hwsiii]

Re: Looking for right prop size and pitch HELP

What are the recommended WOT RPM as well as the gear ratio for your motor.

H

 

[Tow Joe]

Re: Looking for right prop size and pitch HELP

it is a 3 blade aluminum prop.

 

[Tow Joe]

Re: Looking for right prop size and pitch HELP

Recommended WOT is 4200 to 4600 rpm as to gear ratio i will have to check and get back to you.

 

[junior1113]

Re: Looking for right prop size and pitch HELP

open up your wallet and get a ss 3x17p or step up to a 4X16p bout the only way your going to pick up any speed. this is if the motor is running like it should and theres no growth on bottom of hull would also check for water loging. stainless props produce better performance esspecialy top speed