Few More Horses!!!!!!!!!!!!

brooks1340

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Jul 30, 2013
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Boat is 1985 Four Winns has mercruiser 140.

Boat set for several years in field, bought it and trailer (cheap!!!!) and started rebuild. Have corrected most issues and replaced/rebuilt most everything and even had it in the water several times.:joyous:

My first bigger boat (use small John boats on river in KY) so wanted to buy cheap beginner, plus gives me a new project.
Now I am looking for a way to get a few more ponies out of her, have been tunning on harleys for a while getting the most HP possible for pennies on the dollar and was wanting to do the same on this boat. Any tips and tricks would be greatful:joyous:
 
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achris

More fish than mountain goat
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May 19, 2004
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27,468
Re: Few More Horses!!!!!!!!!!!!

That 3 litre block is just about at its limit at 140 horsepower. Merc added fuel injection a few years ago and had the same thought as you. They got it to 155 horsepower, for about 20 minutes. Then the bottom end let go. That's why they are still 140 horsepower, even with the injection.

If you want more power, sell it and put a V6 in....

Chris......
 

brooks1340

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Re: Few More Horses!!!!!!!!!!!!

Not really what I wanted to hear, was hopeing with some carb tricks and hotter ignition I could squeeze out a few more.
 

Bondo

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Re: Few More Horses!!!!!!!!!!!!

Not really what I wanted to hear, was hopeing with some carb tricks and hotter ignition I could squeeze out a few more.

Ayuh,... Good tunin' is important to help get what's there,...

Hot Roddin' a 3.0l won't get any "Noticeable" hp increase,...
 

achris

More fish than mountain goat
Joined
May 19, 2004
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27,468
Re: Few More Horses!!!!!!!!!!!!

There's no doubt you can get more power, but the 'cost' is longevity...
 

aerobat

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Jun 1, 2011
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Re: Few More Horses!!!!!!!!!!!!

and hotter ignition I could squeeze out a few more.

be careful, advancing even a little more may result it blows the headgasket, mercruiser afaik even retarded 1 deg in aservice bulletin due to gasket issues. like said this engine gives all it can.
 

brooks1340

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Jul 30, 2013
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Re: Few More Horses!!!!!!!!!!!!

What I was afraid of, o well.
Next question is will a inline 6 bolt up to my outdrive unit or did they use a diff set up.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Few More Horses!!!!!!!!!!!!

What I was afraid of, o well.
Next question is will a inline 6 bolt up to my outdrive unit or did they use a diff set up.

Will bolt straight up, but you'll need a different ratio in the drive-shaft housing... You currently have 1.98:1, and you'll need 1.65:1.

Chris......
 
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