Prop results - Advice Needed!

[Trailblazin]

Hi. I have been able to get results on a prop I have that needs to be replaced.

I run a 16ft Crestliner with Evinrude 40 horse 4 stroke. The prop I have is a Michigan Wheel 11 ½ X 13.
- WOT by myself, I get 32-34 mph but my RPM’s are between 6000-6200. Planes out great! Recommended RPM though is 5200-5800.
- WOT with 3 male adults, 28-31mph, but planes out REALLY slow. Seems sluggish.

Seeking advice on what prop I should get? Would like a prop that pulls 3 males and/or used for tubing.

I am debating between the Hustler or the new Vortex by MI Wheel. LAstly, a dealer told me running 6000 RPM's will not hurt my engine, how much truth is to that?

Thanks

[Surface Tension]

Need more info.
Whats your RPM's with a load?
Your asking a lot from your setup without additional help.

Switching to to a lower pitch prop will give you a better hole shot but will increase your RPM's. Right now your above the recommended RPM's without a load so I would look at ways to get on plane faster without changing the prop. First thing, are you trimming in to get on plane? Secondly, a hydrofoil like a stingray will get you on plane faster and keep you there at lower speeds. Those extra RPM's you have without a load tells me your propped right. Getting you on plane then backing off the throttle a little is what you want.

[Trailblazin]

RPM's with a load, 5900-6000. Planes out Real slow too.

By trimming in, what do you mean? I found that lowering the trim with a load, it did plane out a little quicker. When I am alone, I have the trim high and I fly out of the gate.

Would it help going to a 14P prop? When I back off the trottle a little bit, I lose some speed, and I need all I can get....

[Valv]

Ok, just to clarify how the trim of motor works.
Whe you take off, leave motor all the way down, it will increase your holeshot, then when boat it's on plane, raise motor until you feel max speed or rpms are reached.
From the helm of your boat look at water spray on side, it should be at least the last 1/3rd of the boat, but don't trim too much, or your bow will raise too much and boat will be very dangerous to control.

Try this way, and see what happens, I still think your current prop is too short pitched, 400rpm above max is a little too much. Remember a 40hp is a great motor but it's still a small motor, and 4 strokes are known to be less "quick" than 2 strokes, also if your holeshot is slow, you have to understand that.....it's just a 40hp afterall.

------------------
Val Vignati

www.kvesurplus.com
[email protected]

[This message has been edited by Valv (edited 06-25-2004).]

[Surface Tension]

Your asking that small motor to perform at its best under differing loads. No matter what prop you get you'll have to compromise speed or hole shot. The 14 pitch will bring the RPMs down a little and increase speed but you'll plane out slower. Like I said earlier don't look at improving performance with just a prop. Trim in to get on plane and trim up ounce there and go with a Stingray or better yet a set of trim tabs. Once you do that you might find out you can move up to a 15 pitch. Something additional to try is have your prop cupped. Your hole shot will be the same but you'll increase speed and lower the RPMs.

[Trailblazin]

Thanks. I finally got a hold of a dealer locally and they did recommend a 14P. I'll try the other suggestionson trimming too.

[Trailblazin]

Just curious, but why in the world would anyone recommend a 11 or 12P? I am over RPM's and this is what they are recommeding?

[NotoriousBLM]

Just a quick point here, but I would try to find a dealer that will let you test numerous props to see what works best before you buy. Test both aluminum and stainless.

[TimR]

Well, someone would rec'd an 11 or 12 pitch because you said;
1) you are running a 13 pitch now and it is slow to plane with 3 adults
2) you want a prop that runs well with 3 adults/something about tubing.
3) You can control your WOT rpms with that lever by your right hand.

You can't have it all. Think of two identical cars at a stoplight. One in first gear (13 pitch), the other in 2nd (15 pitch). You will lug the engine away from the stoplight in second gear, but you have a higher top speed.

It sounds liked you are currently propped correctly. Running with people, you are in your rec'd WOT rpm range.

Tim