Can I get more speed out of my 9.9?

mattfish11

Seaman Apprentice
Joined
Apr 17, 2006
Messages
33
I have an early 80's Mariner 9.9 Outboard... It runs really well, but I would like to move just a little bit faster when cruising in my 14ft jon... I run a lot of 10hp restricted lakes so I can't increase my HP...

Will changing the prop do anything to increase my max speed?

Can I do anything to gain a couple MPH??

Just wondering what I could do.

Thanks!

Matt
 

Yepblaze

Lieutenant Commander
Joined
Jun 1, 2001
Messages
1,686
Re: Can I get more speed out of my 9.9?

get a smaller boat
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Can I get more speed out of my 9.9?

Careful tuning of the engine height and trim can often get a few more mph, but unless you have power trim you have to sacrifice take off to get the higher top speed.

Try raising the anti-ventilation plate an inch or so higher than the keel, and trimming the engine out until just short of ventilating the prop or porpoising the boat.

It is unlikely that a prop change would gain you enough to make it worthwhile.
 

rndn

Commander
Joined
May 20, 2007
Messages
2,323
Re: Can I get more speed out of my 9.9?

Make sure that if you raise the motor you always check for the tell tale stream of water. You don't want to fry your motor trying to get another mile or two per hour.
 

mattfish11

Seaman Apprentice
Joined
Apr 17, 2006
Messages
33
Re: Can I get more speed out of my 9.9?

get a smaller boat
That's a big help...
angry.gif
 

mattfish11

Seaman Apprentice
Joined
Apr 17, 2006
Messages
33
Re: Can I get more speed out of my 9.9?

Careful tuning of the engine height and trim can often get a few more mph, but unless you have power trim you have to sacrifice take off to get the higher top speed.

Try raising the anti-ventilation plate an inch or so higher than the keel, and trimming the engine out until just short of ventilating the prop or porpoising the boat.

It is unlikely that a prop change would gain you enough to make it worthwhile.
I've tried to tune it as best as I can I think... Good to know about the prop not making a difference... Thanks!
afro.gif


Make sure that if you raise the motor you always check for the tell tale stream of water. You don't want to fry your motor trying to get another mile or two per hour.
yes.gif

Excellent point... I make sure I look for the tell tale everyt time I'm out... Las thing I wanna do it fry my motor...
 
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