Cant get boat to plane

[lowcountrydigger]

I'm running a 2006 15 horse yammaha two stroke on a 12 foot Duracraft and I cant get it to plane off .When I'm at full throddle the front of the boat pushes down and I cant controll it. When at 3/4 throddle or less it runs fine. And I've adjusted the tilt pen to all the holes without any good results.
Any help or advice will be appreciated.

 

[ezmobee]

Re: Cant get boat to plane

Got any pics of your setup? Do you possibly have a long shaft motor on a short shaft transom?