Prop recommendations

[669dennis]

What is good prop for 19' 2006 Maxum with 4.3 carb . I have a quicksilver aluminum 21p on right now top speed is 40 @4700. I'm thinking smart tabs with a better prop than the quicksilver, just not sure what's a better prop.

Thank you , dennis

[brian0128]

Dennis, your top speed seems low but your rpm's seem good which makes me wonder about the accuracy of your mph. When your doing your top speed run are you trimmed up from full down position to optimize your speed? Are your speed calculations from a GPS unit or from the speedometer? Are you looking for a better top speed or are you looking for a better hole shot. How much weight in people in gear were on your boat when you did the top speed run? The factory prop was an aluminum 14x23 but with your 21" are in the correct rpm range but your top speed seems low to me that's why I asked if you were trimming the motor up and how much weight you have. Also, what is the condition of the current prop? Are there any chips or dings?

http://www.topspeed.com/boats/maxum/...3-ar37520.html This article showed that they tested the 190hp motor in 2007 on a 1900 and got 55mph. Even with your boat loaded with 4 people and a full tank I would have expected a higher top speed in your boat.

I used the Mercury prop selector http://www.mercurymarine.com/propell...elector/#step1 and when I entered your numbers in it shows you have the right pitch prop but it calculated a speed closer to 50mph. This is the site that I would recommend you to choose a prop from but before you go buying a new propeller I would verifiy your top end speed with 2 adults and a half tank of fuel. Start trimmed down and go WOT until your at top speed (verified with a gps) then trim up in small increments. You will be able to see your speed go up as you do this. When your speed stops increasing then trim back down a little bit and record the rpm's and your top speed.

[brian0128]

But to answer your original question I recommend using the Mercury Prop Selector. Members on the forum have said good things about the HighFive and Enertia props. The HighFive would give good acceleration out of the hole for water sports and the enertia would certainly help you get the best top speed out of your boat. These are both stainless steel props and cost quite a bit more than the aluminum props would.

[669dennis]

I was thinking of black max 19p aluminium low speed towing and water sports, but not sure about higher speed thinking 23p? I have the 21 quicksilver aluminium it seems like a good midrange,but not good for water sports just ok..

so give me a good 19p and 23p in aluminm.

[brian0128]

Originally Posted by 669dennis

I was thinking of black max 19p aluminium low speed towing and water sports, but not sure about higher speed thinking 23p? I have the 21 quicksilver aluminium it seems like a good midrange,but not good for water sports just ok..

so give me a good 19p and 23p in aluminm.

For towing and water sports if you plan on staying with aluminum then I would go with a 4 blade prop. Quicksilver Diamond 4, Turning Point Legacy, Solas 4 blade. Until you figure out why your turning 4700 rpm but not getting a top speed over 40 I wouldn't do anything because a higher pitched prop will drop your rpm's.

Answer the questions in the post above and we'll try and help more but we need more information.

When your doing your top speed run are you trimmed up from full down position to optimize your speed?
Are your speed calculations from a GPS unit or from the speedometer?
How much weight in people and gear were on your boat when you did the top speed run?

And finally, I would verifiy your top end speed with 2 adults and a half tank of fuel. Start trimmed down and go WOT until your at top speed (verified with a gps) then trim up in small increments. You will be able to see your speed go up as you do this. When your speed stops increasing then trim back down a little bit and record the rpm's and your top speed.

[669dennis]

Originally Posted by brian0128

For towing and water sports if you plan on staying with aluminum then I would go with a 4 blade prop. Quicksilver Diamond 4, Turning Point Legacy, Solas 4 blade. Until you figure out why your turning 4700 rpm but not getting a top speed over 40 I wouldn't do anything because a higher pitched prop will drop your rpm's.

Answer the questions in the post above and we'll try and help more but we need more information.

When your doing your top speed run are you trimmed up from full down position to optimize your speed?
Are your speed calculations from a GPS unit or from the speedometer?
How much weight in people and gear were on your boat when you did the top speed run?

And finally, I would verifiy your top end speed with 2 adults and a half tank of fuel. Start trimmed down and go WOT until your at top speed (verified with a gps) then trim up in small increments. You will be able to see your speed go up as you do this. When your speed stops increasing then trim back down a little bit and record the rpm's and your top speed.

thanks for recommendations 45@ 4700 did it with gps speedo off a little.

[669dennis]

so you think 4 blade is better than 3 blade? I wish there was some test on these props? for a coparison?

[mmwjr]

Try googling it there some test comparing 3 vs 4 blade props but the results will vary on the prop and boat tested.

[brian0128]

Originally Posted by 669dennis

thanks for recommendations 45@ 4700 did it with gps speedo off a little.

45mph sounds much better than the original 40mph. You never mentioned how much weight you had in the boat on your average day out. If your mind is set on sticking with an aluminum prop, they are cheap at about $100 each if you shop around the internet. Depending on the cupping of the prop and the diameter keeping the same pitch you could see a wide range of results. There are many tests out there but your pitch is keeping you at the correct RPM right now. 4 blades "usually" have a lower pitch to keep the same rpm's that you have now. I bought a cheap Diamond 4 with a 20" pitch to replace the chipped prop that came with my boat. I lost a few mph going from a 21" 3 blade to a 20" 4 blade but I was able to get on plane faster and the acceleration was better.

I ended up replacing that with a Michigan Wheel Stainless Prop for watersports and a Mercury Mirage Plus for cruising so it ended up being a waste of money but it got me on the water and I was able to get accurate numbers to help me pick a new prop. Looking back I wish I had went to a large propeller company that had a prop loaner program to help me get dialed in for exactly what I wanted. Blade shape, diameter, cup and rake came into play and buying props to try out can get expensive.

Good luck with your choices, just make sure that you keep your rpm's in the mfg's recommended range.

[669dennis]

ok thanks for all the info I think once I get my trim tabs I`ll be better off then I`ll start buying props. im thinking I`ll call manufactures and get there advice on 3 or 4 blade I guess that's all we can do unless I find a loaner program awesome guys!