Porposing at 60mph
#2
Charter Member #1093
![](https://www.offshoreonly.com/forums/images/icons/charter_member_star.gif)
Join Date: Feb 2001
Location: Lighthouse Point & Ocean Reef FL
Posts: 660
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
The CG doesn't change as a result of trim, the Center of Pressure does. By trimming up you're moving the CP rearwards, which in turn is causing the boat to rock over on the bow. As it does, this moves the CP (Center of pressure) forward until the leverage of the drive trim regains advantage, and then you rock back, moving the CP back again, in a continuous rocker motion. You might try a bit of down trim tab when trimming the drive out and see what happens. Also, a prop with more bow lift might obviate the need for a higher trim setting, such as a Mirage plus (unless you're already using one and then we're back to issue #1).
Hope that helps.
Hope that helps.
#3
Official OSO boat whore
![](https://www.offshoreonly.com/forums/images/icons/charter_member_star.gif)
Join Date: Oct 2000
Location: Mequon, WI
Posts: 6,157
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
There are a couple of things that could be happening. Is the drive tight? Grab it and give it a good tug upwards. There should be no play at all. Also, what is your prop selection. A different prop my help carry the bow.
#5
Member #2 ....Jeeezz
![](https://www.offshoreonly.com/forums/images/icons/charter_member_star.gif)
Join Date: Oct 2000
Location: Kicked to the curb
Posts: 2,345
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
Too much trim
![Wink](/forums/images/smilies/wink.gif)
__________________
Look Fast *** Sold Sold Sold *** ... F2 Cigarette Top Gun in OSO Classifieds
Look Fast *** Sold Sold Sold *** ... F2 Cigarette Top Gun in OSO Classifieds
#8
Registered
Join Date: Dec 2002
Location: Fond du lac, WI
Posts: 31
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
Powerboat,
I think your'e going to want trim tabs if you don't have them now. I've got the same problem with my Baja Force 235 and have been told by other owners of same that tabs are the only sure fire cure for this boat. They say just a tad down with the tabs stops porposing with little or no loss in top end. I think my deadrise is also 22¡Æ which is probably part of the problem. Ran a 23P last summer and will add tabs this spring. Food for thought.
I think your'e going to want trim tabs if you don't have them now. I've got the same problem with my Baja Force 235 and have been told by other owners of same that tabs are the only sure fire cure for this boat. They say just a tad down with the tabs stops porposing with little or no loss in top end. I think my deadrise is also 22¡Æ which is probably part of the problem. Ran a 23P last summer and will add tabs this spring. Food for thought.