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Old 04-07-2021, 02:09 PM
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Originally Posted by Shooterschmidty View Post
Hello,
I'm wondering if I might be able to get some advice. I recently purchased an 03 18' Cat Craft (very similar hull to the later Caracal) with a 115 Suzuki with a Power Tech, 4 blade 19 pitch SS prop. The previous owner mounted it on hydraulic jack plate with a spacer totaling 12" set-back and installed trim tabs with trolling motors. I find that the boat struggles to get on plane quickly, suffers from some ventilation while accelerating, sometimes porpoises, and will easily rev over 6000 rpm at full throttle. I installed a permatrim which reduced the ventilation and does help the plane, but it's still not where I think it should be. I'm wondering if a different pitch prop would help, or maybe if the large setback on the jack plate is causing excess ventilation and causing the prop to slip? I've played around with jack plate height, trim, etc without much luck. The trim tabs do help bring the bow down and get up on plane, but they add a lot of drag and I don't think they should be necessary on a boat this size. Right now I'm thinking that I might need to remove the jack plate, or at least the spacer, to bring the engine closer to the boat and also remove the trim tabs to reduce the weight in the rear before I try different props. Does anyone have any experience, ideas, or insight they can share? Thanks in advance.
Here is what I remember about your 18' Cat Craft. It was manufactured by C-Hawk boat in NC. I believe their 18' cat was patterned after Angler Boats 19' cat (made in Miami), which like your 18' Cat Craft was not a popular hull due problems caused by the 3rd sponson in the tunnel, & both cats were only manufactured for a couple of years due to owner rejection because of problems like you are experiencing.

That 3rd sponson like your Cat Craft has below your engine, sticks down like a sore thumb and prevents clean water from getting to your prop <- and that is crux of your problem. Did you ever wonder why the previous owner added a hugh 12" jackplate to that little boat? Answer = to try to get his prop down far enough to reach and get a grip in clean water, and that jackplate upsets the entire balance of the boat. You can continue to do as the previous owner did with band aids - like messing with your trim tabs, the Permatrim, or whatever - none of which will be much help. I've been through this before with a 19' Angler cat and what that hull needed was to remove the 3rd/middle sponson so the prop could get clean water, and I don't know how feasible that would be.