Help on Prop Recommedation

[glcody]

My current prop is the OEM 21" pitch prop that gives me close to 42 mph at 4800 to 5K rpms. It performs pretty well with 2 or 3 people. However, when I'm under a load, the hole shot it poor, I experience high bow rise and its slow to accelerate to plan. I want to replace the current prop to see if I can get a little more top end speed as well as choose a good prop for skiing/towing/wakeboarding or general crusing while loaded down. I have bought a hydrofoil to help out on plane, but need to replace the prop as well. Recommendations?

 

[roscoe]

Re: Help on Prop Recommedation

First off, I am assuming you are referring to the boat in your user name, so a 4.3l i/o, recommended rpm range of 4400-4800.<br /><br />Sorry but you have a choice to make.<br />More speed, highly unlikely anyways, as a higher pitch prop will lower you rpm, and also reduce holeshot performance. Actually dropping down to a 20" pitch would put your rpm where they should be.<br /><br />Better holeshot, can be done, but by going to a lower pitch prop you will increase the top rpm's even further out of the recommended range.<br /><br />There may be a prop out there that will help the holeshot without effecting the rpm or top end too much, probably a 4 blade.<br /><br />Sounds like you have about the best you are going to get to me, but I'm am not a rigging/setup expert. <br /><br />IMO, 3 things could be happening here. The boat is overloaded, the boat is underpowered, or your expectations are too high.<br /><br />How much money are you willing to spend to go 3 mph faster, and burn more gas to do it?<br /><br />Your best bet may be to add a set of Nauticus Smart tabs to help on holeshot and boat attitude. They would do much more for you than the hydrofoil.<br /><br /> http://www.iboats.com/mall/index.cg...rt tab&**********=609825164&*******=749281044

 

[roscoe]

Re: Help on Prop Recommedation

Hey, no fair, now you changed your user name while I was typing.<br />In that case, I have no idea if you are running an i/o or an outboard.

 

[glcody]

Re: Help on Prop Recommedation

My boat is Mariah Barchetta 18.5, 4.3L Mercrusier V6. Thanks for the tips, the main reason I'm looking to change props it the one I'm running is already a "spare" prop and it's been worked on a bit. I just bought the boat in Jan and when I did, the seller suggested I consider a new prop. I've considered going to a 4 blade, but if they're so much better why aren't most boats with 4 blades?<br /><br />I'm just looking for some advice as to what others with simialr boats have found in terms of performance. I'm probably looking for two props, one for cruising and the other for skiing/wakeboarding.

 

[Terry H]

Re: Help on Prop Recommedation

Baracudda <br />there is a forum specifically for i/o boats. Perhaps the folks there would have some better advice there than here on the outboard motor forum. Chief

 

[glcody]

Re: Help on Prop Recommedation

Thanks, I'll repost!

 

[JB]

Re: Help on Prop Recommedation

I/O topic.