jack plate question

[greasemonkeyjmj]

i was told by a mod to post in the prop section. sorry if it is in the wrong place. i have a 95 procraft v200B with a merc 2.5 XRI it has a 10inch setback manual jackplate on it. i have never ran with a larger displacement engine, or with a jackplate, therefor i am lost on how to set it up.right now, using a straight edge along the pad, and measuring from it ,down to the center of my nosecone is about 6 and 1/2 inches. i have a feeling this is way to low. i was thinking around 4 and 1/2 was a good starting spot. any info would be appreciated.

 

[steelespike]

Re: jack plate question

I'm not experienced with the more high performance setups but
There isn't necessarily a specific demension for your setup.
Actual demension may vary even between identical setups.
Raise the motor a little at a time to a point just before venting becomes a problem.Check best trim for each position.Make only one change at a time
and check it out.ie: don't change prop and height at the same time.
Once you have the best height a prop change may allow even more; thats where the experts can really help.Allways be sure it is pumping water.

 

[Frank Acampora]

Re: jack plate question

Ten inches set back is a lot and it gives a lot of leverage and bow lift. Generally speaking, the farther the set-back, the higher the engine can be set. The higher you run it, the faster the boat will go--to a point--but the longer it will take for the prop to "lock up" and get the hull really moving. Of course, this assumes that water pick-up does not become a problem. And, when you get into this performance range1/8 to 1/4 inch difference can make a really big difference between sterling and mediocre.

I'm not too sure, but I think you want to run a highly cupped prop.

If you get a racing nose cone and a low water pick up, you can then run even higher and faster with a surface running prop and just the lower half of the gearcase in the water but then, it takes forever to get the prop to "lock-up" with a manual jackplate.

If you are set up with such a jackplate, your hull surely isn't a general purpose hull. SO: why don't you do a search (Procraft.com or Procraft on iboats forums) to see if there is a website or forum for your hull and see if there are others with an equivalent set-up who can give you more specific info?

 

[greasemonkeyjmj]

Re: jack plate question

thanks for the info guys.i am just kinda looking for a baseline starting point on where to run it,the way it is, when i go to take off the water will come up past where the bottom of the cowling seals onto the engine itself, until i get on plane. i can see where someone has ran with the jackplate all the way up at one time. the engine just came from the shop, after being rebuilt because of someone burning it down. the man i got it from had just bought it and never owned a boat.so i thought maybe the mechanic had lowered it for a little insurance on the new guy not running it to high and losing water pressure. what was really different was the man i bought it from had purchased it to duck hunt with in the timber. i dont know, but i figure a 7 and 1/2 foot by 20ft long bassboat would be hard to maneuver in the brush LOL