just a little faster...

ferrariman

Petty Officer 3rd Class
Joined
Jan 4, 2006
Messages
82
Does anyone know of any fairly inexpensive way to squeeze a litle extra power out of a two stroke 1989 25 hp johnyy. I have already put in a larger card and intake manafold wich gave it a little extra go ecspecially off the line
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: just a little faster...

What is your max rpms at WOT? And - where is the cavitation plate relative to the bottom of the boat? This will tell us if you are getting the maximum out of what you have.
 

ferrariman

Petty Officer 3rd Class
Joined
Jan 4, 2006
Messages
82
Re: just a little faster...

The cavitation plate is exactley inline with the bottom of the boat and and max rpms are 5700
 

lark2004

Lieutenant Junior Grade
Joined
Jul 12, 2004
Messages
1,080
Re: just a little faster...

you could probably come up a little bit, try 1/2 to 1" and see what happens. Don't let it rev over 6000. Also be carefull not to go too high and lose water presure to your cooling system.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: just a little faster...

is the boat loaded properly, gas tank, battery(if elec start), passergers, all balanced bow to stearn, port to starbord. will help
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: just a little faster...

Now youre talkin'! I wish you had the thru hub style lower unit but thats OK. As mentioned, watch your water pressure, thats very critical. But dont be afraid of rpm. We've turned that style powerhead more rpm than you'll ever get to. As long as theres a load on the prop we're OK. <br /><br />Again -- as mentioned, try raising the motor some. I'd go up a 1/4" at a time and record the results. It all depends on the hull design right now. You'll get results something like -- change, gain, change, gain, change, same, change, lose.<br /><br />Make one change at a time!!! IE -- dont change load and height and then test. Change the load then test. Then change the height and test again. One change at a time!
 
Top