Set-up question

[Neilslure]

Got to run my ZX 250 yesterday WOT long enough to figure out she would stroll. Got it up to 72 and still going up and bumping up trim then I noticed my water pressure had dropped real low so I backed off and trim back down and it came back. I am guessing I need to drop the jackplate a little.

1. How do you adjust it?
2. How far should I go?

[-BjBnet-]

try just 1/4 inch at a time.
First bring it down maybe an inch or so,run it...take notes, then bring it up 1/4 at a time till you find the sweet spot while taking notes every time you make adjustments....wind and current direction, temp air/water, fuel level...anything that can affect your speed.
I know you know all that, but I'm sure someone will give you an idea of approx. where the sweet spot is

[K.D.]

Measure your prop height and we can go from there.

I know it's been covered a lot but if you don't know how, here are the basics in just a couple of easy steps. Do this on a smooth, hard surface such as a garage or driveway.

1) put a level on the centerline bottom of the boat and level the boat using the trailer jack.

2) lower motor and put level on cavitation plate. Level motor.

3) Measure height from floor to bottom of hull at the centerline.

4) Measure from floor to the tip of the bullet on the nosecone. (this is the same as the center of the prop shaft)

5) Subtract the prop shaft number from the pad number and that's how many inches below pad you're currently at. If you're above pad, we need to talk!

As far as adjusting it look at your setback plate. The bolts on the side have to be loosened and the large bolt in the center facing down is then turned to either raise or lower the setback plate. Use the difference in the two halves (where they split) to keep track of where you're at. (Measure the split before and after making the adjustment)

You'll probably end up being at about 2.75" below pad, but you need to know the other info to properly setup your boat.

[DavidnTex]

What rpm's were you at, height of enginer and what prop?

[deer0373]

Mine is admittedly a smaller boat/motor but 2.75 below pad seems to be what she likes.

[Neilslure]

I was probably between 5700 and 5900 RPMs. Prop is a Yamaha 27 T-1