Ranger 350V Reprop

Miller_Murdaugh_Fish · January 08, 2019, 01:21:15 PM

Hey yall, I have a 85 350v and it is powered by a 85 blackmax xr2, the boat runs really good, i'm a little worried about rpm's though, right now its turning a 21p laser 2 at about 6k to 6100 and it will run about 62-63 with optimal load, I was told that the 23p tempest was the deal for my boat, any input?

Mike Cork · January 08, 2019, 01:31:35 PM

It's hard to say, each boat reacts different to different props. But your numbers sound like you have a lot of slip right now and the 23 Tempest could help with that.

Do you have a buddy that has a 23 pitch anything you can play with and see how it effects the numbers?

Miller_Murdaugh_Fish · January 08, 2019, 01:34:32 PM

I do not, I wish I did but the boat it self has a great holeshot ands hits top speed very quickly. do you think I should go to a 4 blade?

Mike Cork · January 08, 2019, 01:46:47 PM

Your hole shot is awesome because you can turn the current prop so easy and get the RPM's up quick. You'll obviously sacrifice a little of that with a bigger prop.

This is part of the prop conundrum. A larger pitch can bring your RPM numbers down and give you a little more push through the water. A four blade prop can also do the exact same thing but results vary.

Sorry I can't be more specific. Looks like your goal is to get your RPM numbers down, if you are wanting to gain a mph or two while doing that then I'd stick with the three blade and try the Tempest or even a Fury.

A four blade will drop your RPM's and give you more stability, generally doesn't jump the speed much. But I have seen a four blade prop lift more boat out of the water and pick up speed.

I think you're about maxed on your speed for that boat and motor 58-62 was the speed range depending on load. The Xr2 motor can handle staying in the 6k range but you'll increase the longevity if you get it into the 5850 to 5900 range. A 23 pitch prop could do this for you.

Miller_Murdaugh_Fish · January 08, 2019, 01:56:14 PM

ok thank you very much, so now I just have to decide between a fury and a tempest, would you go with the tempest? ive been told that was the deal for my rig.

Bud Kennedy · January 08, 2019, 01:56:47 PM

I agree that the top end performance you are getting is very good for the boat and motor you are running. I don't think I have ever heard of one being able to turn the rpms you are listing. I would expect somewhere in the 5800 category as well. If you are not concerned with the high rpms then I would leave it alone, if you want to bring it down use the 23. I have a 365V with 150hp faststrike and I would be concerned at that rev level. I achieve the same performance as you with a 4 blade running at 5800 I can turn 58-60 with ease and the hole shot is average not great but ok. It would be interesting to know what your prop to pad measurement might be.

Miller_Murdaugh_Fish · January 08, 2019, 01:59:47 PM

Quote from: Bud Kennedy on January 08, 2019, 01:56:47 PM
I agree that the top end performance you are getting is very good for the boat and motor you are running. I don't think I have ever heard of one being able to turn the rpms you are listing. I would expect somewhere in the 5800 category as well. If you are not concerned with the high rpms then I would leave it alone, if you want to bring it down use the 23. I have a 365V with 150hp faststrike and I would be concerned at that rev level. I achieve the same performance as you with a 4 blade running at 5800 I can turn 58-60 with ease and the hole shot is average not great but ok. It would be interesting to know what your prop to pad measurement might be.

Its a quick little boat, im just not very comfortable running that high of rpm on a older motor, Im definitely going to get a 23p prop I just need to figure out whether to get a tempest or a fury

Mike Cork · January 08, 2019, 02:00:50 PM

Quote from: Miller_Murdaugh_Fish on January 08, 2019, 01:56:14 PM
ok thank you very much, so now I just have to decide between a fury and a tempest, would you go with the tempest? ive been told that was the deal for my rig.

The Tempest was used a lot on your set up. I love a Fury prop and drive a heavy boat as well. Have you been to the Mercury website and used their prop finder tools. They have a page where you can plug in your stats and it will suggest a prop. How close it is I have no idea.

Bud brings up a good point on your prop to pad measurements?

Miller_Murdaugh_Fish · January 08, 2019, 02:06:04 PM

I have no idea on the prop pad height, I bought the boat used and the set up im running is what he had on there, the boat itself is pretty light, I believe boat and trailer weigh about 2800-2900lbs, Im pretty sure the boat loaded down is about 2200-2300lbs

Miller_Murdaugh_Fish · January 08, 2019, 02:07:01 PM

and mercurys website doesn't go back to the 85 blackmaxes

Mike Cork · January 08, 2019, 02:10:10 PM

See about getting the measurement before you commit to anything. Your RPM is high so that would suggest lowering the motor, this would put more prop in the water and possibly get you more water through the prop thus reducing slip and raising speed.

The very good hole shot suggest you could come up with the motor still but your already high on RPMs, you you could add a high pitched prop and raise the motor and get more efficiency.

But if your only goal is to lower RPMs for the motor, lowering it could get you that and you don't have to buy a prop.

Bud Kennedy · January 08, 2019, 02:19:37 PM

Here is a graphic to help you determine prop to pad

Miller_Murdaugh_Fish · January 08, 2019, 05:45:11 PM

what should the distance be at?

Bud Kennedy · January 08, 2019, 05:55:30 PM

A typical measurement would be 3 1/2" below pad

Miller_Murdaugh_Fish · January 09, 2019, 06:59:43 AM

ok thank you very much for all the information, im measuring from the running pad to the cavitation plate when the cavitation plate is level right?

Bud Kennedy · January 09, 2019, 07:04:34 AM

The measurement is from the pad to the centerline of the prop shaft.

The basic way is to level the boat then set the motor perpendicular then measure from the ground (hard surface) to the pad and then measure from the ground to the centerline of the prop shaft, the difference between the two measurements is the prop to pad number

Miller_Murdaugh_Fish · January 09, 2019, 07:12:29 AM

ok ill get that measurement and bring the numbers back to you

Oldfart9999 · January 10, 2019, 07:01:14 AM

The Fury prop wasn't available when that boat/motor was made.
Rodney

Miller_Murdaugh_Fish · January 10, 2019, 09:01:31 AM

I know that, I have a laser 2 21p on my boat right now, I was thinking about reproping the boat to a 23p fury or a 23 tempest

Oldfart9999 · January 11, 2019, 07:35:17 AM

Is there a place that will allow you to try one before you purchase? I have a friend that needed to reprop his boat, the local BPS let him try several different props to find the one he wanted.
Rodney

Miller_Murdaugh_Fish · January 11, 2019, 07:38:13 AM

Dang I need to find that! that's a sweet little deal, unfortunately the nearest BPS is 2hrs away from me, I need to find a marina or a prop shop I reckon