Overtrimmed but speed increases

[ProcraftWes]

I have read that overtrimming the boat and creating a tail higher than the cowling is wasted energy. I have a 18' fish/ski with a merc xr4 and the boat will run 58-60 ~5800rpms running a 22p prop(gps) but to achieve this speed I have a roost at least double the top of the cowling(prob higher). The boat runs fine turns fine but just seems to me that the motor is set to high. I want this boat to run without having to surface the prop to much because its heavy and has the xr4 lower which Ive read is weak. Here are a couple pics they are the best angle i have and don't know if they will help.
Any suggestions?


http://img38.imageshack.us/img38/4118/96832374.th.jpg (http://img38.imageshack.us/i/96832374.jpg/)

[/URL][URL="http://img37.imageshack.us/i/boat0076.jpg/"]http://img37.imageshack.us/img37/5450/boat0076.th.jpg (http://img20.imageshack.us/i/boat007a.jpg/)

[outboards4life]

put a setback bracket on it. it helps for heavier boats with lesser motors. probably about 6 inches would be good.

[Wizard]

Definately put a plate on it. Your engine is too high. Yes your speed is better because your using the trim to leverage the hull out of the water but your not effecient trading rpm for leverage by increasing slip. If you lowered your motor your prop would slip less, grab more water and leverage the hull better. You would also lose rpms in doing so. But by lowering the prop pitch to get your r's back up you'll gain back your speed with better handling.

Now adding a plate will make it better because your using setback to leverage the hull instead of trim. You'll probably not need a new prop you'll just adjust the plate correctly and use less trim. :cheers:

[ProcraftWes]

I'm keeping my eye out for a manual jackplate with 6" setback.. thanks guys :cheers:

[jphii]

I'm keeping my eye out for a manual jackplate with 6" setback.. thanks guys :cheers:

LOOK HERE (http://forums.screamandfly.com/forums/showthread.php?t=193510)

[Carter Powell]

Here is another idea that often gets overlooked. Set back/Jack plates do give you increased leverage to help the problem that you have encountered. There is something else that you may want to consider that often is left out! How much bow lift does you current prop have built into it. I have seen many problems cured just by having a prop that will carry the bow properly. Not saying that this is the cure but it could be part of the problem.
Many times a set back/ Jack plate will cure the problem and that is a good place to start but if you don't get the absolute results you are after then go to the prop. All of these things combined can really make a huge difference in the total performance of your boat.

Best of luck, Carter Powell

[ProcraftWes]

would 10" be to much?