what prop do i need

[rightcoastrob]

can someone tell me where the numbers are on a merc 1979 inline 115 hp.i have a pair of these motors on a 22 ft stuery osf fishing boat.i have a bad prop hub and just want to order 2 new props.im pretty sure its a 15 spline just not sure about the pitch.i also read that if u have dual motors u may wanna go a step higher in pitch is this true?

 

[rightcoastrob]

Re: what prop do i need

after reading through the forum some more here is some more info.not sure on the weight of the boat i belive its 3400 lbs plus another 600 in motors.and id say at least another 500 of gas batterrys and other stuff.the beam is 8 ft.the plate above the prop i dont know the term is approx 3 inches above the bottom of the v rpm operating range of 5000 to 5500 rpms i do belive.as stated before my hub on the one motor is slipping so im not totally sure where the rpms top out as of now.

 

[crb478]

Re: what prop do i need

Pull one of the props off and see if there are any numbers or if the pitch is stamped into the hubs. If it only list numbers you will need totry to cross reference the number to find the diameter and pitch. Most props will have either a number or the size/pitch stamped into the hub somewhere. A few do not, those have to be taken to a prop shop to determine the size. A prop shop can also rehub your current prop and balance both props to make them run like new.

 

[rightcoastrob]

Re: what prop do i need

These props are beat up pretty bad fried of mine had his done at the shop here and payed 86 bucks.and it took a week i can order from iboat and have it in 3 days for just a few more dollars.And i took both my props off today and found no numbers go figure.