Prop for a 1998 evinrude 25h

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May 24, 2010
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I just recently bought a 14ft pelican bay skiff w/ a 25 h evinrude 3 cyl. The prop that is on it is a 10x13. It has a hard time planeing with myself and one other guy. Any suggestions on which prop I should buy to help this problem.
Thanks
 

Kamdyn

Petty Officer 2nd Class
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Oct 25, 2009
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Re: Prop for a 1998 evinrude 25h

I would go with a 10 pitch for more torque so you can plane easily.
 

steelespike

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Re: Prop for a 1998 evinrude 25h

Need a lot more info to make an accurate suggestion.Not knowing your present ,max rpm and speed its impossible to select a correct prop.Did you try trimming in one notch.Is the antivent plate (just above the prop)at least even with the bottom of the boat?Yes a 10" pitch will help your load ability but could add over 600 rpm to the present max rpm.leading to a possible over rev problem and poor top end.
If you had a tinytach and a gps we could get you dialed in.Improving your overall merformance and economy.
 
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Re: Prop for a 1998 evinrude 25h

Unfortunately I do not have tach...A friend of mine suggested going down 1 pitch to a 10x12, because he was also worried about over rev. The antivent plate is approx 2" below the boat. The motor is on its highest setting. How hard is to install a tach?
 
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Re: Prop for a 1998 evinrude 25h

Today I drilled some air holes in the prop like a few people suggested. It def reved up more while trying to plane but i believe it was sucking a bit to much air and still would not plane with me and another guy. Do you think the main reason for this is because of the anti vent plate being 2" below the boat or a prop issue?
 

steelespike

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Re: Prop for a 1998 evinrude 25h

It sure doesn't help so low.You could probably raise it 3 inches a 2 inch change can result in 2 mph.in ideal conditions.The mounting bracket doesn't need to sit on its lip
as long as you can bolt it securely to the transom.Ive seen pictures of about 3'
from the transom to the lip. You may have to get a jack plate.These set the motor back getting it into cleaner water and allows finer higher adjustment.You'll probably have to plug those prop holes.A tiny tach is about $40 and easy to install.Perhaps you could borrow a gps for speed or clock it with a friends boat.A change to a 12" pitch I think makes sense.Your motor is struggling now and isn't likely to over rev.
Unfortunately without the rpm and speed your motor could still be struggling
even though it planes easier.Over time a motor that is lugging can develope premature repair problems. especially with today doctored gas.It also wastes fuel
 
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Re: Prop for a 1998 evinrude 25h

Thanks alot for your help. I ordered a new prop off this site, i am going to try a 10.5x11 and see what happens. I cant afford a jack plate right now so hopefully this prop will work. One last question, what should the max rpms be on my motor?
 
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Re: Prop for a 1998 evinrude 25h

I went ahead and bought a jack plate today.Got it for 75 bucks at a surplus store. I will let you know how everything works. Thanks again
 

steelespike

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Re: Prop for a 1998 evinrude 25h

You should do one or the other first. Another words install the jack plate and test,then do the prop.or prop first and test then jack plate.Makes more sense to me to do the prop first.
Great; raise the motor to a point just before venting becomes a problem.
If you got the 4 blade Amita you should be able to really raise the motor.
 
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Re: Prop for a 1998 evinrude 25h

I am going to install the plate tomorrow. I bought the 3 blade. I didnt know the four blade would make a difference. Should I return it and get a four. Other than being able to bring the motor up a little higher is there any other advantages?
 

steelespike

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Re: Prop for a 1998 evinrude 25h

The 3 blade is ok for all around performance and top end the 4 blade does really well at low to medium speeds.
Generally a 4 blade gets on plane easier and stays on plane with less power.
usually more effective for manuvers at docking etc.and of course allows a higher motor setting.It is more resistant to slip and venting.It may be a tad slower top end,
 
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Re: Prop for a 1998 evinrude 25h

I installed the jack plate and brought it up 3". I took it to the lake and it got up on a plane with me my dad and my son on board. It was still sluggish but at least it did plane. Major improvement from a few days ago when it wouldn't at all. My prop should be in tomorrow or monday so hopefully that will help to.
 

steelespike

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Re: Prop for a 1998 evinrude 25h

I know you don't have a speedo but could you tell if the top end seemed strong
considering the extra person?You may be able to bring it up some more if you don't have any venting issues.
 
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Re: Prop for a 1998 evinrude 25h

The top end seemed fine just still sluggish planeing. I cant raise it any higher theres no more adjustment on the plate. With the motor now being even should I remove the hydro foil? would this be creating unnecessary drag
 
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Re: Prop for a 1998 evinrude 25h

I bought a tach a little bit ago...it has several settings on the back of it. The guy thought it was supposed to be set on 6p for my motor but seemed unsure. Do you know if hes correct
 

steelespike

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Re: Prop for a 1998 evinrude 25h

Yes the foil could create drag just observe it at speed if its in the water there is drag.If its in ther water it may cause the boat to lay down too much.It does probably help you get on plane but it wouldn't hurt to try without.
The 11" pitch will help a lot.
Can't help you on the tach I suppose you can eliminate some setting by your rpm results.The indicated idle speed may help.Typically around 700 rpm.
 

Al-53

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Jul 17, 2008
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Re: Prop for a 1998 evinrude 25h

I bought a tach a little bit ago...it has several settings on the back of it. The guy thought it was supposed to be set on 6p for my motor but seemed unsure. Do you know if hes correct

if your tach has a 5 pole setting try that I have a 35hp 1983 and was told to go to 6 pole come to find out most engines below 40 are 5 pole got that from a OMC tech any ways I used my tiny tach against my onboard tach and on 5 poles it was dead nuts as the tiny tach.....

Al
 
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