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Engine pitch

G

GigThis

Well-known member
Hey anyone got any input on where the pitch of a GPU 220 should be set. I changed hulls and the new hull does not porpus but feels real crazy when it runs, like the back of the boat is loose. 12' cottonmouth hull front driver, double rear passenger. Sprays water off the hull on plane up where the driver sits in the front of the metal works.
 
I always like to level the boat out under the motor and the raise my motor a 1/8 -1/4 bubble above level Just me you might have to move your rigging around a lil as well to far forward will cause that to happen as well
 
The back of engine at the prop should be higher than the front. If the front of the boat
isn't plowing and your not porpoising it sounds like its set up good. Raing the back
will cause porpoising if its too high, Remember, to gain dry ground performance you lose water performance and vise versa.
 
You may be ablke to change the weight inside the boat some to stop that forward spraying on a plane. Should have no spray foprward of the 1/3 forward point along the hull on a plane, the further back the loser it will handle until your riding on a trim tab.

Some can be done with weight changes some may need to move the engine and rigging. Get your gas tank back some and the battery shoulld be back there too.

Scotty :wink:
 
Sounds like you need to definitely raised the back of the motor up. Putting jacks in will help to. See what is happening is when you mash the gas the front of the boat plows down in the water. That be cause by alot different reason. One namely being the way motor is directing the thrust and if the back of the motor is lower than the front will cause the front of the boat to plow into the water.
 
I'm going to be moving my gas tank further back to stop the looseness on the back end also , my motor is 1/8 -1/4 bubble above level , question is my hull hops a little from time to time by moving the tank back will that eliminate the hoping at all ,.
 
the same think is happening to my buddies boat. We moved the engine and cage back as far as we could. raised the rear of the motor and put a jack up front. Still plows..Now we are thinking it might be the polly????
 
Crabby , if you hull hops from time to time is this as you burn off fuel and empty cooler? If so moving you tank back will increase you hopping to possibly all the time.
 
jimmyflfr":uet2l6ou said:
the same think is happening to my buddies boat. We moved the engine and cage back as far as we could. raised the rear of the motor and put a jack up front. Still plows..Now we are thinking it might be the polly????
Click to expand...

Another thing to watch out for is having the prop to far below the transom. That will also cause the front to plow .
 
That could be a problem. If I remember his prop is a bit low in the hull. But dont have room up high to move it up.
 
Just curious here... I have read in several posts that the back of the engine needs to be 1/8-1/4 bubble higher than the front of the engine BUT no body has said how big of a level to use... Doesn't that make a difference? Wouldn't a 1/8 of a bubble on a 4 foot level be over a 1/2 bubble on a 12" level? Or are you guys using a level that is the same length as the engine? If so when you add a gear box to it should you add to the length of the level also? I would think you would have to but that's why I am asking...
 
I don't think theres a set science to it, it's kind of trial and error as no 2 boats are
set up the same. My 220 ended up with a 1/2" spacer and 2 washers to get it right.
The level just gives you a good starting point in the right direction.
 
Do you have poly or slick bottom?
Poly that is cut too short in the front would cause an aggressive front edge that could drag and cause a spray in the water.
 
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