Boat Prop

[mpdive]

I need to replace my OEM prop on my 2003 Alpha One Gen Two drive. It says J14.25 by 21P. I know nothing about props and was wondering if there is any advantage to stainless other than looks and it being stronger. Some options say 4 blade too. I just need some prop experts to advise me on any advantages of upgrading the prop or just getting the oem 3 blade. Thanks in advance. I am prop challenged..........:facepalm:

 

[Maclin]

Re: Boat Prop

What are the issues with your current prop?

If it is just old and you liked how the boat performed before it got old then I would just replace what was there.

If you are trying to change the performance of the boat then list what type of boating you do (Skiing, Cruising, etc...) and what you want to change in regards to the performance for each type.

Also knowing the engine size, the drive ratio, the current pitch, the top RPM reached at WOT, and accurate speed at WOT will go far in addressing any performance issues that you may have.

 

[fishrdan]

Re: Boat Prop

I need to replace my OEM prop on my 2003 Alpha One Gen Two drive.

Why? Are you trying to improve something? Is the prop all banged up?

SS props flex less than aluminum props, so they will perform better. But, you can't swap a 21P aluminum for a 21P SS and expect better boat performance. 4 blade props will have better holeshot and lower planing speeds, while sacrificing a little top end speed. If going to a SS or 4 blade prop, you will most likely need to drop pitch.

At the top of this forum is the Read This First!! thread. You'll need to do some boat testing and come back with accurate data so the prop guru's can help with prop selection for "your boat".

 

[mpdive]

Re: Boat Prop

Thanks for the replies. We ran a bit aground on the Cooper River and wound up in a rice field last year. This year I noticed one of the blades has a little bend in it. I never noticed any driveability issues after it happened. We boated the rest of the season with no problem. We mostly just cruise around with some water sports here and there. It is a 2003 3.0 liter with an alpha 1 gen 2 drive. The boat is a Stingray 180 LX. Being the original prop and the slight blade bend, I reckoned I might replace it anyhow.

 

[Bamaman1]

Re: Boat Prop

Stainless props are a little faster on top end, but they may be a little expensive for your boat. An aluminum prop will do just fine on your boat unless you're often running in very shallow water, or where you might bugger the prop up.

I'd suggest going on I-Boats and just ordering yourself a new 21 pitch prop for your 3.0 140 hp motor. Their prices are very good, and the 21 pitch is the most popular prop for the 140 hp motor and your size boat.

If you were running a 150 hp bass boat, I'd tell you to go stainless prop in a second. You're not in such a high performance usage, however.

 

[mpdive]

Re: Boat Prop

Stainless props are a little faster on top end, but they may be a little expensive for your boat. An aluminum prop will do just fine on your boat unless you're often running in very shallow water, or where you might bugger the prop up.

I'd suggest going on I-Boats and just ordering yourself a new 21 pitch prop for your 3.0 140 hp motor. Their prices are very good, and the 21 pitch is the most popular prop for the 140 hp motor and your size boat.

If you were running a 150 hp bass boat, I'd tell you to go stainless prop in a second. You're not in such a high performance usage, however.

Thank you Bamaman. Looks like Iboat has what I need for a good price. Thank you for the help

 

[Silvertip]

Re: Boat Prop

Thank you Bamaman. Looks like Iboat has what I need for a good price. Thank you for the help

But you have not determined a benchmark for your current prop. How do you know what to order in a new one? You need to make some wide open throttle runs with what you consider and average load. Note the rpm and speed (preferably by GPS). Then and only then can you make an intelligent purchase. Going into this blind may result in a boat that performs worse with a more expensive prop.

 

[mpdive]

Re: Boat Prop

But you have not determined a benchmark for your current prop. How do you know what to order in a new one? You need to make some wide open throttle runs with what you consider and average load. Note the rpm and speed (preferably by GPS). Then and only then can you make an intelligent purchase. Going into this blind may result in a boat that performs worse with a more expensive prop.

Thank you Silvertip. I really never run wide open witht the stingray due to the Z hull design. I really cant even trim the engine if there is any chop on the water whatsoever. It's one of the quirks of the design. I was going to order the same diameter and pitch of the oem prop that is on there now. I just didn't know about the 4 blade and the changes it would make. Like I stated previously, it performs fine and comes out of the hole well. Just like my body has slowed down, I drive the boat like an old man. I am usually running about 23 mph and leave it there because thats where the boat planes out at. I was just concerned about the slight bend in the blade causing unneccesary wear on other parts. Thanks again for the reply. Much appreciated.