Help with prop questions......

[RWS]

Hi, I was looking for alittle help on a rescent prop swap for my jon boat.

I have a G3 1544 aluminum jon boat with a 2001 Nissan 40D tiller.

The factory prop is a 11x13 aluminum. It does fine, but the hole shot was too aggressive(it would come out way too fast if you give it WOT from a stop). Top speed (GPS) is 31.7 mph with just me(250 lbs), a full live well, and my fishing gear.

I was thinking of going to a stainless prop with a higher pitch so I went to a MW Apollo 10-1/8x15p. Hole shot is great now but speed only increased to 33.0 mph, which makes me think I have excessive slip.

Should I just stick with the new prop or try a diff brand or diff pitch?

It is a better prop and the hole shot is what I wanted, but I thought I would gain alittle more top end speed than a measly 1.3 mph.

I guess what I'm asking is would a diff stainless prop brand or diff pitch give me better top end, but still a less agressive hole shot?

Thanks,

RWS

 

[steelespike]

Re: Help with prop questions......

Without your rpm there is no way to know where your actually at.
Prop size, max rpm and speed Is the key to a proper setup.
You may need to raise the motor(vertically).
Have you adjusted the trim.Trim out.Some jons lay down really flat and can be difficult to get the forward part out of the water.As a starting point the antivent plate should be about even with the bottom of the boat.

 

[RWS]

Re: Help with prop questions......

I have the short 15" shaft so height shouldn't be a problem. The plate is as you described in placement.

It does have power trim so I tuned in minor amounts to get the 33 mph speed. Any higher and the bow bounces, any lower and speed decreases. I did the same with the stock(11x13) prop.

It runs fine with the factory prop (11x13 aluminum). I've been running that prop for 7 years without a hitch, but it's getting scratched a bit and starting to get dings. I wanted a stronger prop and decided to go higher to get rid of the agressive hole shot and gain speed at the same time. When someone would drive the boat that wasn't used to it, it would sort of scare them if they were used to jumping in jons and going straight to WOT. It's a pretty light boat for a 40 HP.

It's a Tiller on a jon, so I have no idea how to tell you what RPMs, but I have run enough outboards to have a good idea of when they are wound up high or lulling. I've heard several lull with too high of a pitch prop. It sounds the same with either prop, it doesn't wind up high or lull.

One thing that bothers me about the new prop is how small it is compared to the stock 11x13. The stock blades are much larger surface area wise and though I haven't measured either(just went by the manu stamp) the 11x13 appears to be 1.5" larger in diameter. I'll measure them when I get a chance.

I was looking at a stilletto and a power tech on the net and for this motor, their 15 pitch props are a larger diameter than the Apollo. Would a larger Dia make a difference? Will the larger dia help the slippage? Seems like it would.

Like I said, the new prop does fine, but I was expecting more than a 1.3 mph gain when going up 2" in pitch.

Thanks,

RWS