Planing out problems

[1986 Cheetah]

I have an 18 foot fish and ski with a 90 HP mercury engine on it. The motor starts and runs fine, every time. However, the boat has been giving me problems planing out.
If I gun the engine, the front pops up, but never quite planes out, and then I have to pull off the gas and let it come back down and start over.
I have tried a few things that have helped somewhat,
1) Trimming the motor up, it seems like it helps sometimes, I just trim it back down after I plane out.
2) Putting passengers in the front of the boat seems to help too, but doesnt quite get the trick done.
3) The only surefire way of planing out is to slowly let the boat pick up speed and kind of ease it into full throttle.

I have never not been able to get it to plane out, it just takes a couple of tries most of the time and is becoming annoying.

Should I try a different whale tail, or prop?

Thanks is advance for your help,

Andy

 

[steelespike]

Re: Planing out problems

What year motor,aluminum/fiberglass boat? size prop (usually on the barrel)what is your max rpm and speed?
trim in(down) until it starts to plane gradually trim out(up)
I think I would check the motor, compression?is it running on all cylinders?
is the throttle opening all the way?is the motor in excellent tune?
Some even don't catch that a 2 cylinder is only running on one.except for the lack of power. If you have a bunch of stuff at the stern you need to move some forward.