Engine wot 4800-5000

Joined
Jul 6, 2012
Messages
8
I have a 1994 procraft 180 with a mariner 150... It's very slow out the hole and will only turn 4800-5000 on top end. It has a laser2 21 pitch prop on it. At wot in runs 50mph. Any suggestions would help thanks
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
12,944
Re: Engine wot 4800-5000

Welcome to iboats

If the engine is in tune, with good compression, and firing on all cylinders with proper setup, poor holeshot and low rpm suggest too much pitch on the prop. Has it always been like that or did it take a turn for the worse?
 
Joined
Jul 6, 2012
Messages
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Re: Engine wot 4800-5000

Had engine checked by mechanic he sayed good spark and compression and is in tune.... I was thinking it was also the pitch but most people have prop with 25 pitch on their 150s does that mean my motor is worn out... I just bought the boat it has been doing this since i had it
 

mr 88

Commander
Joined
Nov 3, 2010
Messages
2,115
Re: Engine wot 4800-5000

Some people think that by over pitching your fuel mileage will be better and top end will increase,wrong on both counts.Maybe the previous owner went that route or your boat is waterlogged.I have a inline 150 on a 15' boat that weighs about 400 lbs and it is running a 21" at max rpm of 6 grand, so I agree with the 19" pitch,what is the max rpm's recommended.Who are most people that run a 25" ? Bass boats with a jackplate?? No way does a 18' heavy boat with a 150 run a 25". Can you borrow a 19" or do you have a spare ? if not maybe buy a aluminum 19 as a spare and see how it performs.
 
Joined
Jul 6, 2012
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8
Re: Engine wot 4800-5000

I have a jack plate on mine..... I'll have to see if I can find a food deal on a 19
 
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Jul 6, 2012
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Re: Engine wot 4800-5000

It's it true that I can put a different power head on my motor and give it more power... If it is then what is it called?
 

1stout

Cadet
Joined
Aug 20, 2011
Messages
12
Re: Engine wot 4800-5000

then it would be called a 175 or 200 depending on which you went with.
 
Joined
Jul 6, 2012
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8
Re: Engine wot 4800-5000

What exactly is the power head I'm new to outboard engines is it the whole top of the motor or a part?
 
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Jul 6, 2012
Messages
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Re: Engine wot 4800-5000

Someone also said if I put carbs,intake plate, and a tuner from a 200 it would give it more power is that true?
 

1stout

Cadet
Joined
Aug 20, 2011
Messages
12
Re: Engine wot 4800-5000

it would be cheaper to buy a different outboard than replacing the power head. Get the motor that you have running good and propped correctly before trying to add more power, otherwise you'll just be causing more issues than you are solving.
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
12,944
Re: Engine wot 4800-5000

People say a lot of things
 
Joined
Jul 6, 2012
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Re: Engine wot 4800-5000

Ok so I tried a 19p today and my Rpms went to 5300 but I only ran 48mph...any suggestions?
 

oldman570

Lieutenant Commander
Joined
Mar 25, 2011
Messages
1,615
Re: Engine wot 4800-5000

Your motor is running as it should with the 19 pitch prop and in the RPM range for best economy. Your boat must be real heavy and be some of the trouble. Next time out run it accross a set of scales and see just what it weights. Also see where the cavation plate on the motor is in relation to the bottom of the boat. If you want to go any faster than the 48 MPH you will need to trade the motor off for a good 235 HP motor if fast is what you want.
 
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