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Kustrud

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Dec 17, 2014
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Braselton GA
Here's the deal, I feel like my motor is trimmed in too much due to the cavitation plate being too low in the water and spraying water all in the back of the boat. You can tell from the side that it'd be slightly pushing the nose down. I think it'd run better and stop the spray if I could trim it up more. However, if I move it out 1 pin, it looks perfect and doesn't spray, but the prop ventilates then once I get on plane. This makes me think the motor is slightly too high on the transom, short transom and short shaft motor. I'm thinking a jack plate is the only way to rectify this?
 
Could be a lot of things.

If it's spraying water up into the boat, generally speaking it's too low on the transom. But if you trim it "out" one hole and it blows out, it could be more than one issue. Slipping hub. Prop design. Turbulent water (from imperfection in the hull?) getting to the prop. Exhaust excessive "leak" between the prop barrel and the foot. IMO it should not blow out if the AV plate is even with the bottom. I run mine about 1.5" up and I feel that it's too low, but can't go any higher.

Jack plate would help as long as the prop will let it run higher on the transom. But, I wouldn't just use a jack plate. I'd use a PT&T. Puts the motor back 5" or thereabouts. The setback alone would let you move the motor up. Plus you'll have PT&T. With PT&T you can remove the trim pin totally. Trim it all the way in, it planes almost instantly, and flat, then trim it to what your setup "likes". Best of both worlds. Normally on most of the WE boats I've messed with, PT&T alone with it's adjustment of motor height usually adds 2-3 mph without even changing the prop. Mess with the prop some and 5mph can be had-easily. Some guys get a lot more. I'd have one on mine in a heartbeat if it would fit in the garage but I don't have 5 extra inches to spare. I have about 0.5 inches to spare, if that.
 
Thanks for the reply Turbo. It's literally dead even with the bottom of the boat, and the hull is perfect, brand new and smooth as can be. Prop and hub are brand new as well as of today so I'm sure that's not slipping. Also, when on the third hole (closer in), it doesn't vent at all so it's not slipping. I still haven't tried it back on the second hole with the new prop so maybe I just need to do that. I measured the height difference with each pin placement from the tip of the cavitation plate to the ground with the boat on the trailer and each pin hole brings it up or down 2" roughly, which is a lot. I'm thinking the sweet spot would be trimmed where I want it on the second hole but an inch lower all together in the water. Does that make sense at all?

Power tilt and trim would be amazing, but too expensive!
 
Panther makes a neat after-market power trim unit for that engine. They are expensive but I always find the money somewhere. It works. I own one. Need it to go fast. (Model 25)

Not sure it will fix your problem though. Couple things to rule out: Measure to see if your engine is exactly in the center. Try 1inch either way see if it makes a difference. Could have the keel feeding air to the prop. Is that boat equipped with a 16in transom? Some are.
Try a couple of different props too see if it makes a difference. If you stay on it, does the prop hook up again? I have had that happen. You have to feed the throttle carefully to not overspeed. As the boat speed increases the prop may just get a better bite. This became a way of life with my MV1648 and a Johnson 40.
 
Yes, it seems like it does hook up again once it gets on plane and I back off and feather it till it grabs. Also, yes I believe it is a 16" transom. Why do you ask, are some short transom boats 15?" This would explain that if so. Power trim is out of the question for this motor, I'd rather wait and spend the money on a newer motor one day. Also, I haven't tried the "proper" trim setting yet with the new prop so that's worth a check too.
 
The cheapest way out of this scenario is to simply send your prop off and have them add cup to the blades.
The way you describe your issue is exactly the way all high performance or Bass boats come out of the hole. They accelerate, slip, then hook up. You are just missing the last part of that. Cup will do what you want.
 
I think I'm going to try it first trimmed out again now with the new prop. The new prop is great but didn't trim it out when I went out, just left it where it was. It's a 10 x 13 AL prop. Can you add cup to an AL?
 
Good deal, I'll let ya know how it goes this weekend when I take it out again with the new prop trimmed up 1 hole.
 
Ok took it out today with the new prop and trimmed out to where it looks more level (slightly more than level in terms of trimmed out and not in). Same thing, prop vents once you take off and have to feather it to get on plane when is loses its grip. Once on plane it's fine and can hold it wide open. If I turn too sharp though it cents as well. I don't get it. I feel like I'm pushing water if I go down 1 pin hole, but it doesn't vent or slip at all and if I go to the next one it's too much apparently. What do I do? Get a jack plate to keep it trimmed out more but also be able to lower it some? Short transom, short shaft motor, cav plate is pretty level with bottom of boat. I'm at a loss. It's fine with just me but I feel like if I add someone up front I'll really be pushing water if I trim it back in. Any ideas? Here's a pic from the side on the third pin hole, the setting where I feel like I'd be pushing water and it DOES NOT vent at all.

You can see the motor angles in but the boat is also downhill on the driveway so it's actually angled in more. Even though it seems to run fine that's why I feel I'm pushing water and spraying over the transom.

 
Put a spacer between the top of you motor mount & the top of your transom. Just measure what you need and go buy aluminum bar stock.
 
That's funny cuz I was wondering that exact thing. Your saying do that but keep it trimmed as is in the pic I posted? (Trimmed in) that would clearly raise it up some but isn't trimmed in too far if the direction my prop thrust is pointed is down instead of parallel with the boat thus making the nose dive? I appreciate the help, first boat I've set up so asking tons of questions.
 

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