Jack Plates
anzomcik
Posted 2/2/2014 10:38 AM (#688888)
Subject: Jack Plates





Posts: 532


Any one running a jack plate? If you installed it what differences did you see before and after. Do you feel it was worth it? Any recommendations on set back, or is the vertical lift the biggest contributor to performance increase?

Its winter, I got time to think and that gets me into trouble. I been rolling the idea around to help with some real shallow water areas I often fish.
MuskyMulisha
Posted 2/2/2014 10:51 AM (#688889 - in reply to #688888)
Subject: Re: Jack Plates





Whats your setup?
anzomcik
Posted 2/2/2014 10:53 AM (#688890 - in reply to #688888)
Subject: Re: Jack Plates





Posts: 532


Ranger 681c, 115 Johnson faststrike.
VMS
Posted 2/2/2014 11:01 AM (#688894 - in reply to #688888)
Subject: Re: Jack Plates





Posts: 3508


Location: Elk River, Minnesota
Hiya,

I have a 4" manual set-back that is adjustable on my 2005 Alumacraft Navigator. I have it up so it sits about an inch or so above the highest bolt hole if the motor was mounted on the transom.

What I saw in doing this was the bow did not jump up as much when trimmed under on hole shot, since the weight of the motor is further back, the center of gravity moves rear ward, making the bow easier to trim. And...with the increased height off the transom, I saw an increase in RPM as well, along with better grip on the water...to a point. The higher you go, the more air that is potentially capable of reaching the prop, increasing prop slip. With the right prop, you will feel like your whole boat is lifted higher out of the water as well...which equates to efficiency and speed.

If you do decide to go with a jack plate, be sure to install a water pressure gauge. Go too high and you could burn up your engine as you lose water pressure the higher you go. My rig runs right about 15 - 16 psi on the gauge where I am at, and have tried higher where it dropped to about 12. I did it one summer and found when air temps and water temps were high, that pressure would drop a tad more...to about 10 and that is starting to run risky. Moved it down a half inch and have not moved it since.

Most boat manufacturers don't carry their warranty to a motor mounted on a jack plate as the further back you move the motor, the weight of the motor puts more stress on the transom. I made sure when I did mine, I considered the largest motor HP it could handle, then found the heaviest motor made in that HP, then did some calculations about how my motor would weigh as compared, being another 4 inches back. I wanted to make sure I was still close to the parameters of the heaviest motor.

Overall, I think they are a nice addition and worthwhile if you like to maximize what your rig can potentially do without going inside the motor.

Install is not too bad if you have an engine hoist and a hoist ring above the flywheel of the motor.

Steve
Ifishtolive
Posted 2/2/2014 12:24 PM (#688911 - in reply to #688894)
Subject: Re: Jack Plates





Posts: 81


Location: Van Buren, Indiana
I like VMS wanted to wring all I could out of my '04 Lowe 180 Stinger with a '05 150 2-stroke Johnson. For calmer waters I ran it with the nosecone of the lower end 1 inch above the pad and saw about 5mph increase in speed. In rougher water I would lower it to 3 inches below the pad when your riding waves or wakes from skier traffic, so you don't run out of water busting the tops. I only ran it at 1" above on big lakes 10,000 acres in bass tournaments, on days when water was calmer. Your holeshots are quicker because it's as Steve said your weight is further back-lifting the front and taking less to plain it up. the whole reason for a jackplate is to lighten the load of water on the prop. Your not turning the whole prop submersed when running WOT thus gaining rpm=gainging speed. I bought a Hydro-Dynamics 6" Rapid Jack it raises with 1/4 in increments and only takes a socket wrench to do it! It is the easiest thing next to hydraulic it ran about $260 but that's been about 7 yrs ago. Most aluminum boat manufacturer's do have the void the warranty clause- but for me I wanted the performance bonus's! I won't own another new boat without one! Good Luck!