Monark Knight 754 and Merc Classic 50 Prop recommendation.

[elwesso]

hey all, great forum you guys have here. Im a long time boat guy and my family has owned a marina since 1946... I also have a mid 60s chris craft commander 23, but thats another story.

Anyway, my latest project is sort of a little out of the ordinary. I have a 2000-ish Monark Knight 754 Chassis. Its kinda strange because my its just a chassis, they used this boat to build the Monark Pro 754, so its exactly like that boat but there's nothing inside of it. Looks just like the picture below, except all it has is a tiller handle motor and a bench seat in the rear, kinda like a jon boat but its got a semi-V hull

On we go, I'm putting on a 86 Mercury Classic 50 (45HP) longshaft tiller with power trim onto the boat. I have already ran the motor on the boat however the prop was so bad that it isnt worth comparing. We actually had to swap lower units because the prop was seized onto the shaft. The motor has an RPM rating of 5000-5500 and has a 1.83 gear.

Im trying to make this thing go as fast as possible, I dont care about how fast it is out of the hole, i just want it to be a screamer..

IM just looking for suggestions on where to start as far as prop recommendations. I know im probably going to have to tinker with pitch and stuff but im looking for a starting point..

 

[WillyBWright]

Re: Monark Knight 754 and Merc Classic 50 Prop recommendation.

Start with a 14.

 

[Silvertip]

Re: Monark Knight 754 and Merc Classic 50 Prop recommendation.

Agreed -- you will probably end up with a 14 or 15P. 13P is pretty standard for outfitted boats in the 15 - 16 ft range. With no interior weight it should be able to handle a 14 or 15. Get the engine height up to the point where you don't lose water pressure. Trim it out and cut 'er loose!

 

[elwesso]

Re: Monark Knight 754 and Merc Classic 50 Prop recommendation.

Thanks a bunch guys!!! Ill try the 14 first and see where we go from there!

EDIT: This may seem like a stupid question, but what will the difference in diameter make? Ive seen some diameters at 10 1/8 and others at 11...

 

[Silvertip]

Re: Monark Knight 754 and Merc Classic 50 Prop recommendation.

Diameter can make a slight difference in performance but pitch, cupping and rake are factors that have far more effect. If you look at say 13, 15 and 17P props of the same type from the same manufacturer there may be slight diameter changes.