Ok So I put a Jack Plate on.......

[Dwayne]

I borrowed a Hawk JP to see how it would work. First off, that thing is a pain in the butt to adjust the screw is on the bottom and very hard to move. Before the JP, the motor was 3 1/2" below pad. My RPM's were at 5200 and the water pressure was at 25 PSI and I could get 67 MPH out of her. With the plate on, I am now at 2 3/4" below pad, about 5800 RPM and the water pressure dropped to 15 PSI and the speed dropped as well to about 63. I think the engine is too far out of the water now, not only because the numbers fell but the rooster tail is above the engine cowling by a couple of inches. The boat handled much better today with the JP and was a more comfortable ride. I was at a lake with an elevation of about 3500 feet, much more than my usuall lake, maybe this hindered the performance as well. Also, if I lower the engine much more the SeaStar will hit on the transom prohibiting me from tilting the motor up enough to attach the transom saver. Is there a way to move the steering cylinder? Do you all think the engine is too high out of the water as well?

Dwayne

[Psychologist]

What you have to know is that water comes off the pad differently according to speed. Imagine running your hand through water. You get that rooster tail effect. You know, the water kind of kicks up behind your hand. What essentially you are doing with the jackplate is making the boat run in less turbulent water. Also it off sets the the weight of the boat and gives you better bow lift. In my opinion, with the jackplate you have, you are not in a good clean area of water coming off the pad. Most people go with 10", I went with 12" and it seems to work out good for me. Another thing to consider is if your jackplate has an offset built in. The further back you go, the more positive offset you can have. Clear as mud? Hope this answers some of your questions?

What is the size of the plate you are using?

[Backlash Ar]

Now comes the big pain part Dwayne...finding the sweet spot. Start by lowering your engine 1/4" and make sure when you trim it out the rooster tail doesn't go over the top of the cowling. (All your adjustments should be in 1/4" intervals). 15psi at WOT throttle is OK, but more is better.

I'm not familiar with a Hawk Jackplate but there are others on the market that are much easier to adjust than what it sounds like that one is. For a manual plate it's pretty tough to beat a Rapid Jack and you can adjust it on the water too. How much set-back does that Hawk Jackplate have anyway?

If you get your prop blue printed chances are you will have to fine tune it again. How was getting the engine off and back on?

[Dwayne]

I used the hobby shop on base to put the plate on and we used a forklift to hoist the engine. It sounds like this plate is not the right one for me. But this will have to wait a while because my daughter had to go in for emergency surgery last night, she suffered a compound fracture in her upper left arm during gymnastics practice. Thanks everyone for the help.

[Tx Champ]

Dwayne, when you get ready to buy one, look at Rapid Jack. IMHO, they build the best manual plate there is and it is very easy to adjust.

[Psychologist]

Yes, I like Chuck's plates. (Rapid Jacks) He builds them right up the road from me. They are easy to adjust and durable. I would look at one when the time is right.

[Dwayne]

Made some adjustments this weekend. I placed the engine pretty much in the middle of the plate and lowered it down as far as it would go. Went to the lake to give her a try and it was very windy and the lake was pretty choppy. I was able to get about 67 out of her so I made several out of the water adjustments and finished with 69 on the GPS at 5600 RPM's and about 22 PSI and the motor is 2 1/4" below pad, the water temp was 63. With this set-up I get on plane in about 2 seconds and achieve a speed of 65 real quick but when I try to get more out of her she starts to chine walk pretty good. I have a slight rooster tail but not much. I am going to raise her up another 1/4" and try to get the RPM's to 5800. Now keep in mind my 25P Tempest Plus is pretty shabby at best with nicks on all of the blades, some are pretty good. Would it be better to have Mark work this prop or get the Fury What do you all think?

Dwayne

[hydro99]

Dwayne,

It sounds like your'e getting pretty close. The RPM's are where they should be and your speed looks good, but I would keep an eye on the water pressure with the motor that high up. Do you have a low water pickup? If not, try epoxying the top two holes on the lower unit. Closing the holes will keep the pump from sucking air and cavitating, particularly when running in a chop. I'm running 3 1/4" below the pad on my Coral and the epoxy trick was needed to keep the pressure up.

Ps. I hope your daughter is doing well.

[Dwayne]

Thanks for the info John and the concern for my daughter, she is doing much better. I don't have a low water pick-up, but if I raise the motor and the water drops I will plug the top holes, thanks.

Dwayne