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Posts: 84
| I'm having a hard time getting the boat on plane I'm running a raker 2 24 pitch three blade stainless steel prop thinking on going to a four blade like 21 pitch prop do you think that will give me on plane better a better hole shot? |
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Posts: 3483
Location: Elk River, Minnesota | Hiya!!
I'm curious of a few other numbers.. what is your top speed and top rpm when itvis just you and your gear?
In almost all cases if you are slow out of the hole, you will be low on rpms at the top as well, so your thought of going down in pitch is most likely correct. The 620 is a big rig, so going 4 blade might be the ticket....but depending on your numbers it may not be needed. Most definitely a good steel like the Mercury rev4 or evinrude equivalent (the old omc shooter prop) would be good props to try in 4 blade.
The numbers will tell a good story.
Steve |
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Posts: 4
| I have a rebel 15x21 prop with all gear and 2 in the boat it tops out at 5900 rpm and about 60 mph ranger has a full windshield. |
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Posts: 47
| Motor year, make and model will help too. Changes in LU gear ratios can make a big difference. |
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Posts: 443
Location: Indiana | For what its worth, I have a 2008 Ranger 620 with 225 HO Evinrude. My boat came with a four blade 21 pitch, and I topped out at 56 mph and 5100 rpm. I tried a few props and my favorite is a 3 blade 19 pitch Viper. I am at 5775 rpm and 58 mph. |
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Posts: 84
| My TopSpeed now is 48 miles an hour the top RPM is 5200 I do have the M2 lower unit gear case it was switched over from the L2 lightning your case I have 3/4 of a tank a gas and with two people I weigh 270 and the two guys I fish would only one at a time they weigh 300 pounds . And at the time I did have my back like I will full of water I know I should not run at full of water if I don't have to |
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Posts: 84
| It's a 2008 Evinrude E tech 250 HO and it does have the M2 gearcase which I understand is a 1.85 to 1 ratio. I do have a 22 pitch three blade Raker 2 stainless steel prop but it doesn't really seem to help much that's why I was thinking maybe a four blade prop. |
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Posts: 84
| Yes that sounds good I would like to have my boat go like what you described your boat going and yes my boat is a full windshield |
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Posts: 3483
Location: Elk River, Minnesota | Hiya,
What are your numbers with the 22 taker?
Steve |
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Posts: 84
| To VMS ,numbers about the same for the 22 Raker prop I try to get in my local ranger dealer but they're so busy I haven't heard back from you know I may be a electronic issue with the outboard? That's I was thinking of getting a four blade prop about a 21 pitch to get that stern lifted better for a better hole shot because it is a heavy boat. |
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Posts: 47
| Stupid question: Are you trimmed all the way down for takeoff? |
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Posts: 3483
Location: Elk River, Minnesota | Hiya,
I wonder how a 20 pitch raker would do.. the raker props are usually about 1/4" larger in diameter and are aggressuvely cupped from tip to trailing edge. Great prop!! I run it on my rig. Going down to a 20 will get you another 400 or so rpms..but that could be more as well as there is a point of diminishing returns on pitch and diameter. My rig, when I tried a 20 over an 18 could only get to 4800 as compared to 5500.
A good 4 blade can do wonders as well.. the extra fun can make a huge difference on lift...
I'd see about a renegade propeller which has the same basic design as the raker, just in a 4 blade. An older model in the shooter could be your next bet. I also would not overlook getting a Mercury rev4 as they have the exchangeable hub. 20 pitch in the 4 blades.
With the lighter gear ratio, you may find going down to an 18 pitch as well... I'd hope not. If rhe 20 pitch cannot be turned in a 3 blade, then I'd be wondering like you about a power issue..
Steve |
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Posts: 84
| Yes Im trimmed all the way down I have a 8 inch jack plate also on the boat and I had at the lowest setting when taking off |
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Posts: 84
| To VMS yesterday around my boat I put the 22 pitch three blade raker on I had my rear live well recirculating so no water gets let in I fished with a friend weighs 190 pounds and he had a big lake wood box to my amazement when I floored the throttle and the boat came right out of water and ran great it's like it was a whole new outboard the outboard revved up and stayed on plane right away I was very happy so I think I solved my problem. I wasn't sure if going from a 24 pitch down to a 22 pitch would make that big of a difference but it seem like it made a world of difference the engine ran so much better and I topped out about 5800 rpm's. I measured with my 14 1/2 inch prop on and I still have room so I think I could run a 15 inch but I'm thinking maybe if I ever get a chance to try out four blade go to a 22 pitch prop and see how that would run. |
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Posts: 3483
Location: Elk River, Minnesota | Hiya,
If you go 4 blade, I would bet you'd need to drop down in pitch as you will most likely lose rpms due to the extra friction of the 4th blade. I'd expect about 100 to 150 rpm drop.
The same would happen going up in diameter in the raker, staying with the same pitch. For every 1/4" of diamter you can expect a change of around 100 rpms up or down depending if you go down in diameter (up in rpm) or up in diameter (down in rpm).
5800 with 2 people in the boat is spot on... Take the extra guy out, and run your gear only without any livewell filled and I'd bet you'd be right around your 6000 RPM.
That raker prop is a great prop!!
Steve |
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Posts: 84
| To VMS yes I think if I go to a four blade I will run a 14 x 21 pitch as there seem to be the most common among many propeller manufacturers as for my three blade raker2. 24 pitch I think the hub was slipping so I got out I got a new hub for it I haven't tried it yet but I'm thinking that's what the problem is but for now i'm going to leave on my 22 pitch three blade Raker since it runs so good thank you for all your tips to you and everyone else I appreciate it. |
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Posts: 3483
Location: Elk River, Minnesota | Hiya,
If the hub was bad, your rpms would be way up but speed way down. I honestly think the 24 raker is just too much pitch to turn. With the numbers you are getting with the 22, you'd be hard pressed to beat that set up.
Steve |
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