Manual jackplate adjustment....

[jwh445]

I have a Pulsare 1850, w/ Merc 175 Optimax, mounted to a 5.5 inch manual jackplate. I would like to LOWER the engine for better all around performance, hence, tubing, skiing and such. I can back off the four side bolts, but after that, I'm lost. There are four nuts, two on top and two on the bottom of a long threaded rod, located inbetween the motor and the transom. Which nut do I turn? Which way to lower the engine? What kind of tool will reach in there?

John

I'm currently at 3" below the pad, I would like to try 6" below the pad.

 

[83PREDICTOR]

If you lower that thing to six inches below it will handle like shizzz with a z.

 

[Vandalizer]

I would honestly think 3" below would be about as far as you wanna go. You are talking about the distance between the propshaft and pad, right? If that's the case, raising it a bit might even help...

 

[Mark]

Here ya go. http://71.18.68.44/jackplate-information/
It's always good to experiment with different heights. Sometimes what is good for top end is not the best for water sports. Try 4 1/2" and then move up 1/4" at a time till you get the best of both worlds. You might actually find it is back at 3".

 

[CHECK16]

This is why I love my Hyd. Jack plate.

I run 6" below the pad for water sports and it works great. The boat will plane faster and stay on plane at lower speeds with a load.It's all about leverage.This is definitely not a performance set up.

For normal use I'm about 3" below the pad.
You might want to start with a setting in between somewhere.

 

[Vandalizer]

I think I need some schooling here...

It doesn't make any sense to me why going DEEPER would help anything besides steering. (more rudder, way less chance of ventilation in hard corners)
It seems like planing speeds would be simply due to hull characteristics and load distribution. The only thing I can think of is that by moving down you can utilize more of a negative trim angle relative to the boat.

 

[CHECK16]

I think I need some schooling here...

It doesn't make any sense to me why going DEEPER would help anything besides steering. (more rudder, way less chance of ventilation in hard corners)
It seems like planing speeds would be simply due to hull characteristics and load distribution. The only thing I can think of is that by moving down you can utilize more of a negative trim angle relative to the boat.

It seems to me you got it all figured out.
No schooling needed.

 

[jwh445]

Yes, I am measuring from the pad to the propshaft. I would like to be able to turn sharper without cavitation, and maintain a plane while traveling at slower speeds (20mph). Thanks for the link, I asked them the question on which way to turn that, (hard to get to) , nut in the middle, to lower the engine. It looks like I need a large, deep socket with a long cheater handle.

John

 

[Mark]

I think counter clockwise is down, but you'll find out real quick. A regular socket should reach unless you have some rigging in the way.
I have mine set at 4 1/2" on the Mate I use for skiing. I find it slips too much in the turns if I run higher. Fact is I never lost any top end. It doesn't throw much of a rooster tail now thou. It was always fun blasting the skier.

 

[JW]

My 2100BR with the 225 Promax and 23" worked Tempest Plus liked to have the propshaft at 4 1/2" below the pad for overall use. Remember, as you trim it high for top end, the motor lifts a few inches anyway so you regain your engine height that way.