1976 javelin 85 prop selection.

[Tkibby]

I have a 76 javelin 85 on a venture 1550 magnum. Just got it in a trade. Runs like a champ, power tilt and trim, hydraulic jack plate, strong motor. But the prop is mangled from previous owner. Tops out around 46mph and 4500rpm before it loses bite. What would be a good stainless performance prop on this set up.

 

[jimmbo]

That engine has an WOT range of 4500 - 5000. That engine makes it 's best power at about 4700 - 4800 rpm

Since you haven't said what the current prop is...
You say it Loses bit at 4500 and 46 mph. Does the engine suddenly speed up and the boat slows down?

 

[Tkibby]

It is losing bite at 4500rpm, and it's a stock aluminum prop that the blade edges were eaten up in shell bar. I will check numbers and post pics.

 

[Tkibby]

The prop that's on it is a solas amita aluminum 13x21. Could the worn edges of the blade make it lose bite?

 

[jimmbo]

Considering you have Jackplate, that will require a prop that can run well undere Partially Submerged condition, the Solas is not the prop you require. Mercury might have some Props that are suited to that operating Environment. Engine cooling will become a problem at higher engine heights

Anything that changes the edges of the prop, or the Contour of the Blade, may have a Negative affect on the Props Performance