Should I Buy A Jackplate

[rkX4TR]

I have a boat project I've been working on since fall, I am getting close to mounting my mercury 115. I'm considering installing a jack plate but I'm not sure if it's worth the money. I am not interested in a automatic/hydraulic model as I do not wish to spend $1500. I really only want it to make sure I can set my motor height properly. Is this worth it in this scenario, or should I just bolt the motor straight to the transom.

 

[flyingscott]

which 115 do you have? 3,4 or V6 or I6 motor? Honestly I would not waste my money on a jack plate for a 115.

 

[cyclops222]

Jack plates are NEEDED in overpowered boats. But they can set the motor farther away from the transom plate NORMALLY used.
Further causing a stern low overpowered boat to squat even lower. Some Jacks can cause a quick boat slow down, to force the stern wake to pour into the boat.

 

[airshot]

Unless your trying to get every single mph out of your boat and motor setup, no, it is not worth it ! However there are folks that will spend big bucks for a couple more mph.

 

[rkX4TR]

which 115 do you have? 3,4 or V6 or I6 motor? Honestly I would not waste my money on a jack plate for a 115.

I6

 

[rkX4TR]

Jack plates are NEEDED in overpowered boats. But they can set the motor farther away from the transom plate NORMALLY used.
Further causing a stern low overpowered boat to squat even lower. Some Jacks can cause a quick boat slow down, to force the stern wake to pour into the boat.

it is a small boat, its a glastron gt150

 

[rkX4TR]

Unless your trying to get every single mph out of your boat and motor setup, no, it is not worth it ! However there are folks that will spend big bucks for a couple more mph.

well I'm not to concerned about gaining a few extra MPH, i just don't want to mount the motor and have it be way to low, and then im stuck with it. or also making it easier to mount a new engine if I decide to re power.
currently where it would sit is 1 inch below bottom of the hull

 

[Chris1956]

I had my Merc 1500 on a jackplate on my 16' speedboat. It caused the boat's transom to sit lower in the water, but provided a bit of extra speed. The transom sitting lower in the water was an issue, as the weight of the motor was more than the builder planned for, as the boat was rated for an il4.

Another drawback is that power trim has less effect when the engine is mounted higher using the jackplate. So, if you want to trim up the bow when running at high speed, you will get less effect from the trim setting. Still another drawback is that the motor must be trimmed all the way down, each time you try to accelerate from idle, or the prop blows out. That proved to be a PIA.

I ended up taking the jackplate off the boat, and bolted the engine to the transom, pretty high up, so it had less/none of the drawbacks of the jackplate, and most of the advantages. I lost a bit of speed, but not very many MPH.

My advice, put a piece of wood on top of your transom to raise the engine a bit. A 2x2 is probably about right.

 

[rolmops]

well I'm not to concerned about gaining a few extra MPH, i just don't want to mount the motor and have it be way to low, and then im stuck with it. or also making it easier to mount a new engine if I decide to re power.
currently where it would sit is 1 inch below bottom of the hull

Do you mean the cavitation plate sits one inch below the bottom of the hull?
If so you should try to raise it that one inch. Seeing that these 115s are bolted onto the transom you should be able to raise the engine by clamping the engine just a little higher.

 

[Chris1956]

If the IL6 has the older style clamp bracket which uses 3/8" carriage bolts, they do not have much adjustability.

 

[rkX4TR]

Do you mean the cavitation plate sits one inch below the bottom of the hull?
If so you should try to raise it that one inch. Seeing that these 115s are bolted onto the transom you should be able to raise the engine by clamping the engine just a little higher.

Yes the cavitation plate sits approximately 1 inch below the hull

 

[cyclops222]

Your Glastron is a 156 ? A 15 footer ? You want SPEED.