best prop size

[boatguy123456789]

hey i have a 17' boat with a 1987 90hp mercury 2 stroke straight six on it. i use the boat for tubing and wakeboarding and i need to get a new prop for it and theres no numbers on the one i have and i was wondering what the best pitch and everything would be to do what i do with it. any help would be great thanks

 

[steelespike]

Re: best prop size

Without your performance numbers (max rpm and speed,prop size) We really can't be sure what prop would be best for your specific application. Have you looked under the prop nut for a number?

 

[boatguy123456789]

Re: best prop size

yea i looked everywhere. i was hopeing someone had the same set up as me and could tell me what they use

 

[steelespike]

Re: best prop size

yea i looked everywhere. i was hopeing someone had the same set up as me and could tell me what they use

If I had to shoot in the dark I would start with a 17" pitch aluminum. Some dealers will let you exchange props till you get the right one.You will need a tach to confirm your rpm.
Also some way to check speed to evaluate the performance.A prop shop can measure your prop.Don't worry about diameter;if the prop is intended for your motor the diameter will follow.As pitch goes up diameter goes down.