Motor adjustment/jack plate for new aluminum bass boat

[busyone5]

New to the site here, so first question: I recently purchased a new Crestliner VT18 aluminum bass boat. It is fitted with the new Mercury 115 Pro XS 4 stroke motor. The dealer placed the motor in the second hole from the top, they said they found that hole worked the best, and when I asked, they said it was not recommended to add a jack plate. After having the boat out on the water, there a few things I've noticed. One, when I trim this boat, I can ONLY do it with a very small adjustment. Small bumps on the trim switch seem to have a major influence on the boat. Just a little too high and the motor cavitates. I can trim the motor, get the boat on plane and everything seems fine, until I go into a sharp bend of the river, or decide to turn suddenly, then it cavitates. Should I move the motor to a different hole, and what is everyone's opinion on a jack plate on an aluminum boat?

[Skeeterbait]

What prop are you running. You may can improve on these problems with a prop change.

[busyone5]

I have the new Merc Spitfire X7 prop RH 19 pitch. Again, the dealer stated this is what Mercury recommends, and since Mercury and Crestliner are owned by the same company, Mercury will do performance tests on the Crestliner boats. I was putting my faith in them that their recommendation is accurate. But that may not be the case.

[Panama]

I suggest to contact your dealer. I think Crestliner will send you some trim tabs for it if they call the factory. I believe you silicone them on and that takes care of it.

[Skeeterbait]

Yeah that prop should bite well and not cavitate. Same prop I am running on my Ranger and no problems with it cavitating on my rig. Not real familiar with that hull so I agree with Panama check with the dealer/manufacturer and see what they recomend.

[alabamaphoenix]

Crestliner says a jackplate will void the warranty.

[bbarras85]

I had cavitation problems with my boat I've been thinking the motor was too high, which it probably still is but I went to my dealer and bought a pack of exhaust port plugs and completely plugged them. All of the cavitation and vibration at slow speed is gone. It may have hurt my hole shot just a little but nothing to be concerned with.