wrong prop?

[mrmushroomman]

I recently bought new boat and the guy i bought it from put a new prop on. When i looked at the pitch it is a Vortex 14.25x23 pitch. I am running a 4.3 lx mercruiser with alpha 1 gen ll outdrive with 1.84 ratio in a 180 Sea Ray. This prop seems way to big. The factory prop calls for 13.75x21. I ran the boat briefly before i bought it and it seemed to be close to my wot range but my whole shot was terrible and i didn't drive boat long because it was snowing. My question is will this prop hurt anything having that big of a pitch? My mechanic said that before i buy a new prop that i need to run boat on plane and see what my wot is.I don't know why the guy put this size prop on. I just want to make sure i'm not tearing the motor or lower unit up.

 

[rndn]

Re: wrong prop?

As long as it's running in the upper area of the WOT you're good to go. If you want to help with hole shot you might want to look at smart tabs.

 

[mrmushroomman]

Re: wrong prop?

I'm not to worried about the hole shot. I know i can't have best of both worlds, quick hole shot and better top end but i want the best prop for having a decent hole shot and a decent top end. Smart tabs would not be practicle for this boat for it is a 18 ft bow rider with 180 hp. I guess i just need for the wheather to break and take boat out and run it to see how it performs. I will proably keep this prop for spare and buy 21 pitch for better performance. It sucks because this prop is brand new and i just bought the boat and could spend the $100-$150 on something for the boat that is more needed. Oh well that's part of owning a boat huh?

 

[EdForsythe]

Re: wrong prop?

For all around best use you should prop the boat so that it turns the redline at WOT with a normal load. The redline (never exceed rpm) is the high WOT number. I don't think the 14.25x23 will do that. AAMOF I would be surprised if that prop got you in the WOT range. It is absolutely essential that the prop you choose gets you in the WOT range. All manufacturers recommend getting close to the top of the range so that you have some slop when load increases or the bottom gets fouled. NEVER run a boat with the wrong prop because you will be overloading the engine at *any* rpm. That's something that many don't understand. Having said that you must run it to determine whether you have the correct prop. But be careful. If it becomes apparent that the engine will not reach the WOT range don't push it. Back off, go home, and change props. Good luck.

 

[steelespike]

Re: wrong prop?

I would think once you decide what prop is best by running it you could sell the 23 and if you want a spare pick up an inexpensive prop.

 

[mrmushroomman]

Re: wrong prop?

I'm going to try to sell the prop but the problem is that not many people around here are using that pitch prop.I do know about the wot range and that i need to make sure i'm running within the 4600-4700rpm range. When i took it for the test run i only ran the boat for about 200 yards and i don't think that was enough to see what my wot with this prop was. We had 3 people aboard and it was VERY cold (SNOW STORM) and the boat had been winterized priar to test run. Also found that the spark plugs were black and not gapped right so i put some new ngk plugs in her and gapped them correctly. SHe ought to run alot better and hopefully in the next couple weeks wheather permiting, i can run her to see what kind of response i get out of this pitch prop.