I want a stump pulling prop

jraut

Cadet
Joined
Mar 17, 2009
Messages
18
I'd like to get more low end for pulling slalom skiers with a loaded boat. Boat is 20' Chap with 270hp Volvo. I'm currently using a 4 blade 18P Stainless prop, which turns right at 5000 rpm (max for the engine). I really don't care if I lose a bunch of top end - I think I've gone full throttle 4 times in the 4 years I've owned it. Top speed is 48ish, and I'd be happy with 40mph. The lowest pitch available in a High Five prop is 17". Another option is a four blade 15P prop. Would you guys recommend either of these, or is there something else out there that'll pull better? (I realize I'd have to watch the rpms at full throttle if I switch to one of these)
 

JJJ

Petty Officer 2nd Class
Joined
May 12, 2005
Messages
158
Re: I want a stump pulling prop

I would try one of the Solas BIG diameter props such as
15 1/2 X 17 3 blade or
15 1/4 X 18 4 blade etc.

You don't list a year or model of drive, so it is hard to say what is avail.

Go on Iboats here and check the propellers, maybe try an aluminum one - due to cost and see if it meets your needs.

I know the big diameter 15 3/10 X 19P Solas prop helped my Cobalt alot out of the hole.

Their 3 blade aluminum version is just over $110 so you wouldn't be out of alot of $$.
 

JJJ

Petty Officer 2nd Class
Joined
May 12, 2005
Messages
158
Re: I want a stump pulling prop

Just put the info in the iboats propeller page and see what is available for your boat.
 

hwsiii

Commander
Joined
Jan 25, 2009
Messages
2,639
Re: I want a stump pulling prop

Jraut, please tell me the exact dimensions and Make and model of SS prop you are using right now.


H
 

jraut

Cadet
Joined
Mar 17, 2009
Messages
18
Re: I want a stump pulling prop

The prop on the boat now is a Mich. Wheel Apollo 14.37" dia by 18P 4 blade stainless.

JJJ, there's a ton that are available. I'm hoping to find someone that may have used one of the lower pitched props specifically for skiing. Last week on the lake it took forever to plane with 6 guys in the boat and a 250lb skier on the rope.
 

hwsiii

Commander
Joined
Jan 25, 2009
Messages
2,639
Re: I want a stump pulling prop

In my opinion, the Apollo is not the correct rop for what you are using it for. You need a stern lifting prop or a prop that lifts the whole boat out of the water instead of the bow lifting that an Apollo does. I have an apollo on my boat that I use and it works very well for lifting my bow in larger seas but for your uses all it does is dig the stern in more because of all of the weight and placement of it, as well as you are trying to pull a skier up and that just makes trying to get over the hump to plane that much harder.

If you would like me to do a detailed analysis of your setup fill out this form and I will help you.

Iboats Boat and Motor Info

1. Year, make and model of boat
2. Length, width and base weight of boat, look for boat decal on back of boat
2a.What is the maximum recommended HP for your boat
3. Number of people and gallons of gas normally on boat
4. What do you use the boat for
5. Is it a Deep Vee and if so how many degrees of deadrise
6. Year, make. manufacturer and model of motor
7. HP and gear ratio of motor IMPORTANT
If you don?t know the ratio, you need to pull the plugs out and put a piece of tape across the prop and the lower unit and then cut it between the prop and the housing then do the same thing on the motor and turn the motor until the tape lines up with each other on the prop, it is easier if two people do this, so one can watch the prop while the other counts the revolutions of the motor
8. Manufacturer?s recommended Wide Open Throttle (WOT) range
9. Anti-ventilation Plate height above keel of boat if it is an outboard in inches, use a board under the keel and stiking out to the anti ventilation plate for a referene
10. Is it a bass boat or does it have a pad bottom
11. Does it have a hydrafoil, dolefin or trim tabs
12. Make, model, diameter, pitch and whether SS or aluminum prop
13. WOT RPM and speed from your current prop and how much gas and how many people were in the boat for the test data and is the speed by GPS. Make sure you trim the prop up until it starts ventilating and then just trim in until it quits ventilating. If you do not have a tach you can buy a Tiny Tach for $ 50
RPM ___________ Speed ___________ No. of people ____________ Gas ________
14. Are you at sea level or a higher elevation, give us the elevation in feet
15. Has your motor been tuned up lately and have you checked that the carburetor butterfly is opening all the way, checked compression, and looked at the plugs and checked spark, all of the foregoing could be the reason your prop is not attaining full RPM
16. How long has this prop been on the boat and why, at this time, do you think it is the wrong prop
17. Does the prop show any damage that you can see
18. What problems are you trying to cure or what are you looking for the boat to do that it is not doing the way you think it should or to your expectations
19. If you are trying to attain a better cruising speed and fuel savings or trying to attain a faster speed I will want you to take your boat and run it with 1 or 2 people and give me the RPM and speed readings starting at 3,000 RPM in 500 RPM increments all the way to WOT.

REMEMBER, The numbers I give you will be NO better than the information you give me

The only thing I ask of you is to come back and give me a report of WOT RPM and speed for my database.


H
 

JJJ

Petty Officer 2nd Class
Joined
May 12, 2005
Messages
158
Re: I want a stump pulling prop

He will give you a more exact answer.

If you can give hwsiii all the info he requires and he can probably get you close, other option is to just try a few to see what happens.

Maybe search for a shop that will let you try a prop ?

http://boatpropellers.iboats.com/Vo...34101/?**********=073068083&*******=403079534

Might work?

I have a 20' Cobalt, it had a smaller dia. 4 blade SS (forget brand - top name though) prop on when I got it. Just didn't give enough lift.
All I know is going to the big Solas Amita 3 - 15 3/10 X 19P, worked well for tubing and lifting the whole boat up out of the water.
I also have (no longer made) a VolvoPenta 4 blade alum. prop 14.25 X 19P that performed very close to the Solas.

I use aluminum due to cost and where I boat. ie. shallow
 

JJJ

Petty Officer 2nd Class
Joined
May 12, 2005
Messages
158
Re: I want a stump pulling prop

hwsiii is it possible to go to a too low of pitch prop and just overpower it with HP?
 

hwsiii

Commander
Joined
Jan 25, 2009
Messages
2,639
Re: I want a stump pulling prop

Absolutelyyyyy, you could easily create so much cavitation that it would hardly move the boat at all if you gave it too much throttle at takeoff.

H
 

JJJ

Petty Officer 2nd Class
Joined
May 12, 2005
Messages
158
Re: I want a stump pulling prop

That is what I thought. Thanks.
 

sleeper

Petty Officer 3rd Class
Joined
Aug 26, 2008
Messages
86
Re: I want a stump pulling prop

I'm hoping to find someone that may have used one of the lower pitched props specifically for skiing. Last week on the lake it took forever to plane with 6 guys in the boat and a 250lb skier on the rope.

It looks like you might need to reconsider what type of boat you have also. You are only going to get so much out of a lower pitch prop. If this is the boats main purpose and this is your normal load, you need to look into a ski boat. Mastercraft, Supra, Moomba, Malibu, etc.
 

jraut

Cadet
Joined
Mar 17, 2009
Messages
18
Re: I want a stump pulling prop

1. 2002 Chapparal 196SSi
2. 19'6", 8'4" beam, base weight 3300lbs
2a.Max HP 270
3. 4 people, 30 gallons normally on boat
4. Use the boat for skiing, wakeboarding, tubing, and cruising. Probably an even split between each.
5. 18 deg
6. 2002 Volvo GXi 5.0
7. 270hp HP, gear ratio I'll have to research (just wanted to get some info up here)
8. WOT range is 4800-5000
9. N/A
10. Not bass boat
11. Smart tabs installed which help a bunch with keeping the bow down. However, they put a crumble on the wake so I bring them up for wakeboarding, which then takes a long time to plane.
12. Mich. Wheel Apollo 14.37" dia by 18P 4 blade stainless.
13. WOT is 4900 and speed is about 49mph. Not sure on gas, and only 1 or two onboard. Speed is from speedo, not GPS.
14. 1000 ft elevation
15. Engine runs great, get full RPM
16. Had the prop for 2 years, I think it performs fine for a multi task prop, but I'd like something that pulls better. I never go above 40mph, so I don't care if I lose top end speed.
17. No damage
18. Want better pull with a loaded boat.
19. N/A

I'll try to work on getting the gear ratio this weekend. Thanks for any help you can provide.
 

hwsiii

Commander
Joined
Jan 25, 2009
Messages
2,639
Re: I want a stump pulling prop

J, in my opinion if you get a 15" pitch 4 blade stern lifting prop you will lose almost all of your wake for wake boarding as it will get on plane too quick and lift the stern up too much too quick. My recommendation is for a 17" pitch Solas Amita or Rubex 4 blade prop that will help lift the boat enough to make your transition to planing slower than a 15" and will also let you wake board at faster speeds than a 15". You should not lose hardly any top speed and your RPM should not change a lot.
This is a hard decision for the correct prop for your boat, the reason being that you need some stern lift to make the transition to planing easier and yet you don't want to lose all of your wake, so you still have enough for wake boarding. I picked the 17" over the 15" so that you will be able to have a higher speed before you plane.


H
 

jraut

Cadet
Joined
Mar 17, 2009
Messages
18
Re: I want a stump pulling prop

Thanks, I just ordered the 17P Amita. I'll be sure to respond with the results.
 

jraut

Cadet
Joined
Mar 17, 2009
Messages
18
Re: I want a stump pulling prop

H,
You mentioned responding with WOT and speed for your database. With the new prop, is there a chance I can overrev the engine (I'm not sure its got a rev limiter?)
 

JJJ

Petty Officer 2nd Class
Joined
May 12, 2005
Messages
158
Re: I want a stump pulling prop

Which Amita?? 3 blade? 4 blade? diameter?
 

JJJ

Petty Officer 2nd Class
Joined
May 12, 2005
Messages
158
Re: I want a stump pulling prop

I would have to say it is a given that you can over rev your engine :)

Keep and eye on the tach and keep her under 4800 or so if sustained.

I'm going to bet the 15 1/4 X18P Rubex 4 blade will end up being your prop of choice - in an aluminum prop.

If you pull that 17P and really overrev it, let me know. I have a the big Solas Amita 3 blades in a 19P and a new 21P that I might be able to let you try.
If you are an honest guy and I get them back!
 
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