| Author |
Message |
    
Jon Schumacher
Member
Username: simadownow6988
Post Number: 4
Registered: 06-2008
| | Posted on Wednesday, June 18, 2008 - 11:29 am: | 
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Hey guys. Have another question for you.
I have a new 08 Merc 50 2 stroke and the pitch on the prop is 13. Is that a good all around prop or is a 14 better. Mercs prop web site says 14 in everything except top speed. I thought a bigger pitch prop would give you higher top speed. Anyways, is there a difference in a 4 blade prop and a 3 blade? Im new at this and dont know much, but with your help, Im sure I will get a great outcome of my motor. Thanks- Jon |
JB
Senior Member
Username: beckerjs
Post Number: 1068
Registered: 11-2005
| | Posted on Wednesday, June 18, 2008 - 11:45 am: |
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run a prop that puts the engine at max rpm with one person no gear in the boat. 4 blade props are really for higher hp engines and higher speeds. lower pitch is better for hole shots, but it also depends on what diameter the prop is. Just go for the max rpm and don't load the engine down with to high of a pitch |
Jon Schumacher
Member
Username: simadownow6988
Post Number: 5
Registered: 06-2008
| | Posted on Wednesday, June 18, 2008 - 12:01 pm: |
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I really dont know how to do that.
My boat reaches 5000 rpm with the 13. Will it not with the 14? |
JB
Senior Member
Username: beckerjs
Post Number: 1070
Registered: 11-2005
| | Posted on Wednesday, June 18, 2008 - 12:12 pm: |
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no, if the 14 is the same diameter and same style (cupped or not)it will drop in rpm. |
Jon Schumacher
Member
Username: simadownow6988
Post Number: 6
Registered: 06-2008
| | Posted on Wednesday, June 18, 2008 - 12:21 pm: |
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I see. Ok, now that I know that the 14 is not the best for me, do they make a 13 with better performance? I have the original aluminum one on and I know they have to be cheaper than most out there as far as value and performance. I just want to squeeze all the performance I can out of my motor. Thanks so much! |
JB
Senior Member
Username: beckerjs
Post Number: 1071
Registered: 11-2005
| | Posted on Wednesday, June 18, 2008 - 12:33 pm: |
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there are many combos of props to try, cupped or not, stainless, different brands and different diameter. If anything it sounds like it's a little low on rpms. Perhaps the dealer would let you try a couple of loaner props. The engine is trimmed correctly, right? |
Jon Schumacher
Member
Username: simadownow6988
Post Number: 7
Registered: 06-2008
| | Posted on Wednesday, June 18, 2008 - 04:06 pm: |
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To tell you the truth, I have no idea if its trimmed correctly. My last boat had no power tilt/trim. I was just set from the factory and I always used it like that. When I start off, I trim it down to keep the nose down and when I hit plane, I trim it up a little (about level). Am I doing it right?
I have no idea what cupped or stainless props have in advantage to factory. What prop would you use? |
JB
Senior Member
Username: beckerjs
Post Number: 1074
Registered: 11-2005
| | Posted on Wednesday, June 18, 2008 - 04:36 pm: |
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stainless is a much better prop, the blades hold there pitch and seem to be more efficient, their downfall is if you hit anything. Instead of bending and giving they break something, usually something expensive. A cupped prop has ridges along the edge of the blade, they grab the water a bit better, better hole shots, a little less rpm then a standard aluminum. Play with the trim a bit, trim the engine once on plane for max rpm. If the nose is too far down then the rpms will be low, to far up rooster tail and cavitation. Suggest running that prop till you need a spare, if you plan on tubing or skiing or hauling 3 buddies get a lower pitch prop or slightly smaller diameter to increase rpms |
Jon Schumacher
Member
Username: simadownow6988
Post Number: 8
Registered: 06-2008
| | Posted on Thursday, June 19, 2008 - 09:43 am: |
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Ok, thats what I will do.
I got my boat back today from the dealer and he took it out on the river and ran it. He said he had it up at 5600 RPM and running 37mph. The manual says that the range is 5k to 5500. Is what he did ok? Is that a good speed at wot? |
JB
Senior Member
Username: beckerjs
Post Number: 1076
Registered: 11-2005
| | Posted on Thursday, June 19, 2008 - 10:20 am: |
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sounds like he trimmed the nose up a bit more than you did, rpm sounds good for 1 person. Now if you really want you can try the 14p prop and see if the speed picks up, it won't pick up more than 2 mph. But it really depends on how its trimmed and the amount of weight in the boat during normal use. I'd leave it alone. Throw some beers in the boat, grab the dog and leave the wife at home, see if you can duplicate the mechanics speed and rpm and just enjoy |
Jon Schumacher
Member
Username: simadownow6988
Post Number: 10
Registered: 06-2008
| | Posted on Thursday, June 19, 2008 - 10:47 am: |
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Will do!
Goin out tomorrow for a all day fishing trip with a buddy.
Thanks for all your help! |
