New Prop. Thinking about a hustler turning point

[JFW1]

As a quick precursor, I'd love stainless. It's not in the budget now though.

I have an old four blade comprop that I'm using. It's been decent for me. It's a 17 pitch. Prior to that I used a 15 pitch prop that came with the boat when we bought it new, but it cavitated like crazy in the turns.

Engine is a 112hp Johnson SPL. Boat is a Sylvan Sport Select 16, fairly light. I use it mainly for fishing (poorly) and tubing the kids and their friends. According to the manual my redline is 5500RPM. I can overspeed using the 17 pitch prop, but just (maybe 400 RPM). I'm the only driver so I'm not too worried about it, I rarely run it above 5200 RPM (again, can't afford to repair a motor right now). I'm looking at a four blade Hustler 13.25 X 17; the numbers given to me by the iboat website when I put in my motor.

My questions:

A) Can I go straight from a Comprop to an aluminum and expect similar engine performance? Mainly I'm worried that maybe the aluminum won't flex as much and I'll lose more RPM than I should. If it goes downa little, I'm not worried.

B) The Hustler seems to be pretty well raked; will this negatively affect my RPM's? I don't want to lug the engine.

C) It's a vented prop. Does the engine ever overspeed during the wholeshot because of the induced aeration?

D) I've now seen two videos where it looks like people have had to cut their trim fin (I'm not sure of the correct name, I'm speaking of the fin that hangs down from the cavitation plate and is adjustable left or right). Is this normal? I would think a prop spec'd for a boat should just fit.

Thank you very much for any responses!

 

[9758JB]

Well personally I put a new hustler on my johnson 70 and had plenty of room between the trim tab. I think alot of the modifications done are on relatively smaller outboards

As for overspending the engine, I assume you mean over revving? I highly doubt that would be a problem. I tried a hustler 17(with ports) and a 15 without. Even without the ports the 15 climbed rpms faster letting me planed faster. While using the 17, I never had rpms shoot up without acceleration. And at higher rpms a vacuum causes the ports to "seal" so shouldnt slip there.

 

[Texasmark]

And at higher rpms a vacuum causes the ports to "seal" so shouldnt slip there.

Actually new water running past the lower unit seals off the ports. Port size determines amount of RPM increase in the hole. To really get the noticeable effect on rpms, you have to have a non ported prop and firewall the boat in the hole checking rpms vs time out. Then install the same prop, same load, same conditions with ports and check the difference in rpms, aka rpm rise. As the ports are adjusted larger, this rpm difference will increase.

The later model, round port, Mercury Laser II to name one, has different sized plugs so that you can tune your boost to suit your rig. I liked to set mine for 1k initial boost. Got me up the fastest.

On port boost vs lower pitch, obviously it depends on the amount of each.

 

[JFW1]

I'm not sure if the Turning Point has plugs or not. Hrm... I'll check. I didn't see anything in the ad.

I'm a bit irked because if I buy the thing and use it once, with no damage to it, I suddenly can't return it. To me that's insane but it is what it is. So if I get it and it doesn't work correctly I might be out $150 or so. :grumpy:. Ah well. I have to get a new prop at some point.

I'd love to have a better hole shot, particularly while towing. My only worry is that when I gun it initially it's too much. I do have a 13 pitch prop but the engine seems like it would rev to 7K with that if I let it, so I never use it. But if it does that maybe I can figure out a way to plug the holes if I like the rest of the prop.

Thank you both for your answers!

 

[jimmbo]

Aluminum can be welded, or patched with Epoxy Putty

 

[Texasmark]

I'm not sure if the Turning Point has plugs or not. Hrm... I'll check. I didn't see anything in the ad.

I'm a bit irked because if I buy the thing and use it once, with no damage to it, I suddenly can't return it. To me that's insane but it is what it is. So if I get it and it doesn't work correctly I might be out $150 or so. :grumpy:. Ah well. I have to get a new prop at some point.

I'd love to have a better hole shot, particularly while towing. My only worry is that when I gun it initially it's too much. I do have a 13 pitch prop but the engine seems like it would rev to 7K with that if I let it, so I never use it. But if it does that maybe I can figure out a way to plug the holes if I like the rest of the prop.

Thank you both for your answers!

JB weld works just fine. I take a tap and run threads in the hole...I think mine were ⅜" on a TP 4 blade I plugged. Then clean up everything....I like Brake Parts Cleaner aerosol. Then put a piece of tape on the inside of the barrel behind the hole and fill from the outside till the outside is smooth. Works just fine.