how to increase horsepower

geoff pont

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Dec 18, 2009
Messages
11
how do you go about increasing the horsepower of a 1989 evinrude 30hp to35hp is it as simple as changing the carburetor any help thanks
 

kenmyfam

Supreme Mariner
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Aug 10, 2006
Messages
14,398
Re: how to increase horsepower

Bottom line in my opinion is to buy a bigger motor.
Most likely possible but for the expense involved a bigger motor is probably the best way to go.
 

tx1961whaler

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May 31, 2008
Messages
5,197
Re: how to increase horsepower

Maybe. Go to http://shop2.evinrude.com and pull up the 30 HP and 35 HP and compare the parts list. They may also be ported differently, so you'd have to see if the crankcase part numbers are the same.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: how to increase horsepower

usually different carbs or carb jets, porting, exhaust system. you are better off getting you boat and motor properly set up. weight distribution, engine height, proper prop for the combo.
 

qwackhead

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Joined
Dec 1, 2009
Messages
26
Re: how to increase horsepower

how do you go about increasing the horsepower of a 1989 evinrude '"ae30balced"to35hpis it as simple as changing the carburater any help thanks

i believe your motor is a two cylinder if it is that is as good as it gets if it is a three cylinder you can change to 35 hp carbs takes three almost $1000 best to just buy a new motor
 

geoff pont

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Dec 18, 2009
Messages
11
Re: how to increase horsepower

i believe your motor is a two cylinder if it is that is as good as it gets if it is a three cylinder you can change to 35 hp carbs takes three almost $1000 best to just buy a new motor

yes it is a twin cylinder i have found a carburetor off a 35hp omc and wondered if by changing would it do the trick i am in new zealand and outboards are expensive items to replace
 

geoff pont

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Joined
Dec 18, 2009
Messages
11
Re: how to increase horsepower

Maybe. Go to http://shop2.evinrude.com and pull up the 30 HP and 35 HP and compare the parts list. They may also be ported differently, so you'd have to see if the crankcase part numbers are the same.

Yes as far as i can make out they have different numbers so dont know where to go for shelter now maybe stick to 30hp i have a 35 hp carburetor and will compare them to see if any difference
 

Chinewalker

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Aug 19, 2001
Messages
8,902
Re: how to increase horsepower

Actually, your motor IS the 35hp. They made the powerhead rated 35hp up to 1984. Beginning in 1985 they started rating the motors at the propeller, so it was re-rated to 30hp. Exact same motor.

So, putting a 35hp carburetor on your 30hp will achieve nothing.
 

tx1961whaler

Vice Admiral
Joined
May 31, 2008
Messages
5,197
Re: how to increase horsepower

Actually, your motor IS the 35hp. They made the powerhead rated 35hp up to 1984. Beginning in 1985 they started rating the motors at the propeller, so it was re-rated to 30hp. Exact same motor.

So, putting a 35hp carburetor on your 30hp will achieve nothing.

In 1989, there is a 25,28,30, and 35 HP listed. Are they all the same block?
 

geoff pont

Cadet
Joined
Dec 18, 2009
Messages
11
Re: how to increase horsepower

Actually, your motor IS the 35hp. They made the powerhead rated 35hp up to 1984. Beginning in 1985 they started rating the motors at the propeller, so it was re-rated to 30hp. Exact same motor.

So, putting a 35hp carburetor on your 30hp will achieve nothing.

thanks for the info much appreciated kind regards geoff
 

kenmyfam

Supreme Mariner
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Aug 10, 2006
Messages
14,398
Re: how to increase horsepower

So, what boat is this on Geoff ???
 

Genonbamagirl

Petty Officer 2nd Class
Joined
Dec 9, 2008
Messages
134
Re: how to increase horsepower

And how does it perform as is ???

Putting a 35hp carb on a 30hp engine will achieve.........an unbelievable pain in the hind quarter area. There is nothing you can do to the engine to accept the larger carb that will make any of it work.

Get your engine running correctly and sell it. Then buy a good running engine that is larger. Install it.
 

Genonbamagirl

Petty Officer 2nd Class
Joined
Dec 9, 2008
Messages
134
Re: how to increase horsepower

Putting a 35hp carb on a 30hp engine will achieve.........an unbelievable pain in the hind quarter area. There is nothing you can do to the engine to accept the larger carb that will make any of it work.

Get your engine running correctly and sell it. Then buy a good running engine that is larger. Install it.

The difference between a 30 hp and a 35 hp on a 15' boat is not noticeable by people who don't own the boat. If the engine is right the jump in performance is going to be pathetic. Go to a 50+/- or don't upgrade at all.

A 30hp on a 15' craft should scare people - wtf?
 

df909

Petty Officer 1st Class
Joined
Nov 28, 2009
Messages
333
Re: how to increase horsepower

Have you thought about a new prop? I have an I/O and started a thread about increasing power because I wanted to shoot out the hole faster. I could've done some expensive motor work, but instead I switched to a 4-blade prop with a different pitch.

Good luck.
 

Chinewalker

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Joined
Aug 19, 2001
Messages
8,902
Re: how to increase horsepower

In 1989, there is a 25,28,30, and 35 HP listed. Are they all the same block?

Yes. All of the 31.8 cube engines use the same cylinder block, crank, rods & pistons (within a given year). If you look at the parts lists, the 20 & 25 use different intakes and carbs. The 30 and 35 are grouped together on all the pertinent items... I think they did it as more of a price-point thing than any real difference in horsepower. Lots of tinnys out there with max ratings of 30 or 35hp, so they made motors to fit either...
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: how to increase horsepower

Hi this motor is on a 5metre tinny

We can help you get an ideal setup so trhe motor will be able to work at its best.
A little investment in your time could net 2 or 3 mph with no cash outlay.
 

mikesea

Lieutenant Commander
Joined
Oct 1, 2006
Messages
1,830
Re: how to increase horsepower

Move up to a 48 or 50.If your boat can handle a 60-70 3 cyl,then you will find alot more mph.trim and tilt is a big help
 
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