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Old 04-09-2021, 07:34 AM
Senior MemberCaptains Club MemberPLEDGER
Join Date: Sep 2003
Location: CA & San Carlos, Mx
Posts: 23,668
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The tunnel height, or top of the tunnel on your cat is very low, so the air being funneled into the tunnel from the bow has no where to escape to as the top of the tunnel at the rear is fully submerged. You therefore will have to have the antiventilation plate, the Permatrim and the prop below below the level of the keels and bubbly water to get cleaner water to the prop. It probably will never be completely clean even if you lower it a lot, but your prop will ventilate less the lower you go. As an example, my cat tunnel is 25" tall for my 25" motors, so even at rest there is always 7-11" of air between the top of the tunnel and the water surface where air can escape up and away before it gets to the lower level of my props. Your tunnel looks to be about 10" high.

Removing the tunnel sponson is not practical structurally and because the tunnel top is so low, that will really not alleviate the air trapped your propeller water either.. Moving the motor closer to that center sponson will however shield the lower unit and reduce a lot of the splash up you are getting.

Because you have air trapped in the tunnel, your transducer is also probably getting bubbly water and the previous owner probably positioned its as low as possible to get a better signal. The profile on your skimmer transducer is as narrow as they come, so I believe that the setback on the lower unit of your motor is causing a lot more splash and the Transducer and untillyou get the bow down, you will not be able to set the transducer perfectly anyways because the stern will raise and the bow drops, so first things first.

I believe that the 4 blade prop is the way to go. The long setback and high positioned prop are what you need to address first to get the boat riding with only a 2-3 degree attack angle using a neutral trim angle on the engine and Permatrim.

So I agree with First Light in that this model will probably never run perfect, but I am sure we can get it riding faster, dryer and smoother than it was when you got it, and no hull is perfect that I have enjoyed either.

Last edited by Bullshipper; 04-09-2021 at 09:03 AM.