General Prop ?

[fmf]

Hi all. Quick question (and yes I did search) I have a 1985 Bayliner 19.5 with an 85 Force 125, I am going to replace the 3 blade alum. prop because it is very badly nicked and beaten. I dont have measurements because I cant read any of the #'s. I want to replace with a prop that will be best for pulling wakeboarders, skiers, etc. My shop is very fishing boat oriented so I am skeptical they will be able to advise me on the correct pitch etc. for my situation. For the sake of assumption I will say the prop is original, whatever size that is . Any cost effective suggestions would be appreciated, I know for proper recommedations you would like WOT RPM's etc, but I dont have that info yet, boats not even running right now. Thank You.

 

[fmf]

Re: General Prop ?

Addendum: If it helps, last summer boat was running 36MPH at 5000 RPM (WOT) with two adults in it. BUT I dont fully trust either the speedo or tach,just didn't have the time or funds to fix/check either. I am sorry if the info is too general, I am just trying to get general sizes and pitches for props better suited for towing before I start tweaking everything. Thank you.

 

[Silvertip]

Re: General Prop ?

A prop shop can use a pitch block to check your old prop. There is no "standard" prop for larger engines. They are sold originally without them as the manufacturer has no idea what boat the engine will be fitted to. The dealers install what they feel will work best. In your case, I'm guessing but the existing prop is likely a 17P, maybe 19. Since your engine topped out at 5000 RPM, that may be a little on the low side so you want to consider slightly less pitch, or checking engine mounting height to get the revs up a little. AV plate should be even or slightly above the bottom of the boat.

 

[fmf]

Re: General Prop ?

Thank you for the reply. I will take the prop in to have it measured. since i know that I want more holeshot sounds like I should replace with a slightly lower pitch. Also I am wondering about diameter, do i go with the same size, larger, smaller? Thank again.

 

[Realgun]

Re: General Prop ?

Diameter does not matter that much, except to clear the housing, its pitch and cup that matters. Your boat proably has a 19 pitch I would try a 17 however dont rev that motor higher than 5500rpm.<br /><br />17 is what was on my 85 but being 5000 ft I need a 13 and I have the smaller liner 1700 and the 85hp motor.