prop selection issues

[blakeb]

Hello to all i am in need of real world advice, i run an alumacraft 175 navigator cs with the 115 yamaha oubaord both are 07 model year,.

The river ate up my stock prop which was an aluminum 13" by 19 pitch

I decided to go with a 12.75" by 21 pitch after talking to my dealer and a buddy

I used to be able to go 42 mph and had a great hole shot with a top rpm aroung 5700

I now can only achieve 39 mph and get it up to 5150 RPM the hole shot is still pretty good

What prop should i have gotten? i would like to get it up to 44 mph or so if thats possible

[PerchJerker]

I can't help you much with the right prop for your boat, but my guess is 5700 rpms is pretty close to the max for your motor, maybe 6000? Anyway, the point is since you are close to the max with your original prop, that is probably a good prop for your boat. Going up in pitch like you did drops the rpms, and at 5150 I think you're running too low and risking long-term damage to your motor.

I'd go back to your dealer, and maybe even give alumacraft a call and get a prop recommendation from them. Good luck getting it sorted out.

[Esox_Magnum]

I run a Skeeter deep V glass 17' with a 115 and a 13.25x17 and get a great holeshot and about 42 on a good day with 2 guys and loaded. Turning about 6000, would like to try a 19 once just to see what happens.

[blakeb]

esox you got a f115 yammy 4 stroke?

[311Hemi]

See if you can return that prop and maybe give propmd or soderblooms a call.

If I were you I would try a 13.25" x 17 powertech stainless steel prop and see how that does. I am running a 13.25 x 16 Powertech stainless prop on my 1850 Sportfish with the F115 and I top out around 38 mph at 5900 rpms's. You boat is probably a bit lighter so I would guess the 17 would get you close to top performance/RPM's. You may be able to run an 18 and gain a little mph. You want to be as close to 6000 as possible. As PJ mentioned I would not run the prop you currently have that tops out of 5150 rpms.

[Esox_Magnum]

No I run a vintage 2 stroke Merc

[blakeb]

ok thanks for the tips fellas.

I refuse to run a stainless prop, im i run the river and have a pretty good shot at hitting something more so at night when you cant see a floating log or submerged one very well. that is my lower unit insurance.

Esox are you on a stainless?

[Esox_Magnum]

Nope not untill I find one cheap, just running an alum 3 blade Quicksilver

[blakeb]

so you guys think that the 13.25 by 17 pitch would work good seeing as my boat is lighter than your or would that have an adverse affact on the props performance, what does the increased diameter do any ways?

[Esox_Magnum]

Guessing not a huge weight difference between your 175 and my glass, my last rig was an older 175 Trophy and they arent light. Major difference is in hull design, I have to think the 13.25x17 is a good choice not sure you can go any bigger on diam without hitting something. If you have a place that will let you try different pitches try one first.

13.25 is the diam that I think you have to stick with the pitch you can try untill you find the best fit for your boat/motor combo.

[311Hemi]

13.25 x 17 Aluminum Hustler is what came on my boat when I bought it. It ran around 5200 RPM and topped around 37-38 mph. It had bad cavitation and would blowout on turns.

I can understand the need for aluminum on the river. If your going to run aluminum I would try a 17 and see where your RPM's end up and go from there.

[blakeb]

hemi what motor are you running?

[311Hemi]

02' Yamaha 115 4 stroke on an 02' 1850 Sportfish.

[mojoputter]

I can't help you much with the right prop for your boat, but my guess is 5700 rpms is pretty close to the max for your motor, maybe 6000? Anyway, the point is since you are close to the max with your original prop, that is probably a good prop for your boat. Going up in pitch like you did drops the rpms, and at 5150 I think you're running too low and risking long-term damage to your motor.

I'd go back to your dealer, and maybe even give alumacraft a call and get a prop recommendation from them. Good luck getting it sorted out.

Like Perch Jerker says, find out what the max is on your boat or you will damage your motor. I've changed props on my boat a few times, and after reaching 5100rpms I know I should not go any higher, although I have had it up to 5300 rpms, but after seeing what kind of damage it can do I no longer push the mark of 5000 rpms.

[Northlander]

I have a 115 yamaha 4 stroke and I do believe Max RPM is 6000 I run 5800 at WOT

[PurpleHaZe]

I have a 115 Yamaha 4 stroke and I do believe Max RPM is 6000 I run 5800 at WOT

I'm looking at a SS prop just need a little help before i buy. What size prop do you have NL? Being our boats might be the same or close to in weight and same motor. Ive been Trying to call J Soderbloom but haven't been able get hold of anyone. Right now i have a 13 17 h1? its pretty worn out its hard to read ,the other number is 25805?

[Northlander]

E-mail me and we can test my stainless props on your boat. I have 2 different ones. I believe the one I run now is a 13 1/4 by 17 Turbo and the other is a 13 1/4 by 19 or something like that. 17 gives way better hole shot and only about 1-2 mph less at WOT. I get about 38-41 mph give or take a few here and there.

[PurpleHaZe]

Thanks for the Reply. I'm thinking 17 as that's whats on there now?? 40 -41 is my top speed @ about 5800 rpm , If you remember, who i am? you probably do. I had the hydra thing on the motor, when you stopped over with the windshield? Anyways it fell off with my trim tab on our trip to Rainy last week. The boat still gets up with out it but, a little doggy. I would defently test any thing out to get a feel what i need to start with. I will E- mail ya. see what the best days are to test it out?

I know youve posted and others about JSoderbloom. Are tahy still in buisness im also likeing what i see about those Ice houses he sells

[PurpleHaZe]

I went with a 13 1/4x 17 turbo. Was right by the door when I came home from work yesterday, tried it out this morning and I like it allot. Seems to bite alot better and hold the boat up in the chop. So far so good. Couldn't open it up all the way with out slipping a disk in my back. Lake Superior was a little ruff this am. Ill give it a try again tomorrow morning. Thanks NL and HSO forums for the help.And J Soderbloom for taking the time to talk about some stuff Ive read on the forms, Very Nice Guy

[Northlander]

Im glad took care of you.