what size prop do i need? 1989 75 hp. mariner on 17.5 ft alumminum boat. have a 45 hp. merc now, will that prop work on mariner?/ thank you rbass GETTHENET
Rob,<br /><br />Without the WOT RPM's it's hard to tell which prop you need. But a guess would be a 13" X 19". I don't know if the gearcase is the same on the 45 HP(Doubt it). I belive you have the larger V4 gearcase. Hears a list of props for comparison. I-boats also has a good selection of props at good prices. Check out the Mega-mall at the top of the page.<br /><br /> web page
rick, i know rpms, but what is WOT? HAVE NO IDEA WHAT I AM DOING, might buy this 1989 75hp, mariner, has no prop, boat is decked out for bass fishing, it is a 87, lowes commander, need all the speed possible. thanks,, rbass GETTHENET
WOT is Wide Open Throttle. When you are running as fast as it will go. Without knowing that, it's hard to determine which "Pitch" prop would be the best. You must be in your engines correct TOP RPM range for best performance when running wide open. As I said, I would go with the 13 X 17" pitch prop for starters. You can always have the pitch lowered by a prop shop to 15" if nessesary for a nominal charge. I doubt on an aluminum boat you would need less that a 17" prop due to it's light weight. But if you add alot of equipment and a few buddies, that can change things real quick. Then you may have to drop down in pitch to compensate for the extra weight. As you can see, there are many varibles when choosing a prop. Many times a prop shop will let you test a prop and return it undamaged and exchange it if nessesary. That would be the way to go. Also, they know their business when it comes to props and can usually tell you the best one for your application.
