Symptoms of deep prop?

[Kzaker]

I recently repowered this boat and have had it out twice to test various items. First time out with 50g of gas, boat wouldn't get on plane without bow weight. Second time out, got on plane better than it ever has - I had removed all of the vent plugs. But again, with 30 MORE gallons of livewell water, no plane without bow weight. I made an attempt to measure PTP on lunch today but I'm parked on perfectly level concrete, which means I can not lower the front of the trailer low enough for the pad to be level (I'll park it with the tongue off the pad later and get a baseline) but it looks like I'm much deeper than I need to be- would the symptoms I describe correlate with the prop being too deep?

[Kzaker]

Ok so I checked the PTP.

pad to ground: 14 5/8
prop to ground: 10 5/8
Which gives me 4" PTP ?right?
(when leveling the motor, the right side anti-ventilation plate is perfectly level but it seems the casting isn't precise because a level won't sit square on the port side. So these measurements are level from the starboard AV plate)

Now what about the calculation for the 12" jack plate?
Ive heard 1":10", 1/4":1"? Where would be a good place to start? Or ignore that and still start at 3.5" below pad?

So, I'm guessing I should use the jack plate to get me to 3 1/2?

the jack plate is centered right now (top to bottom), I suppose I could go to the local marina and see what they would charge me to put the motor on the picker and raise it one hole (3/4")...

is that necessary?

or just wood block under the skeg and raise it 1/2" on the JP?

would 1/2" make it impossible for me to get out of the hole fully loaded?

[pmgoffjr]

Forget your numbers, let the boat tell you what it wants.
Too low:
Flat/no roostertail
Steering is numb
rpms low for your prop.
speed isn't a reasonable number

So, go to the lake with your regular fishing load, start raising 1/4" at a time until you lose lift, speed, or water pressure, then back to last setting, and you're done. NOTHING else but time and effort will find the exact right setup for YOUR rig.

[Kzaker]

If adjusting it in the water is acceptable: I can do that!

What im asking is are the symptoms I posted indicative of my prop being low?

Id much rather raise it on terrafirma than make my first adjustment IN the water:)

i am pretty sure sure I was at about 3500rps when I was struggling to get on plane LOADED, even with the plugs out it didn't seem to have the Roma to get over the top.

[pmgoffjr]

If you run a rapid jack it's easy if not then you'll want to adjust on the trailer. It's a pain but it's how you find exactly right. Most of the time when you find your best performance number it's also your holeshot number.

[Rip Bass]

You likely have too much prop on that boat. That engine is a 2.5 liter and is known for a slow hole shot. It would help to know your top end rpm too. You might try a Tempest + 24" or a Trophy + 24 or 25. Trophies are a little smaller diameter and can have a better hole shot. But to answer your question,I don't think 1/2" low will kill your hole shot. Assuming your engine is good,you probably have a prop issue.

[turfy49431]

You need to raise it. Holeshot will probably
improve

you should be able to dial in that 25 Tempest

[Kzaker]

The older 175EFI I just replaced did almost just as good (with the same prop) but may have been dialed in better by the previous owner I suppose. Anyways, my plan is to go out Saturday and take some notes but I also am going to get to 3.5" before I depart the driveway. As I understand it: I should see the anti-ventilation/cavitation plate on top of the water correct? I have read that being too low will also push water up in between the midsection and the boat which I am also experiencing out of the hole.

Thanks for the input! I know it'll take time but want to have somewhere to start and I believe 3.5" will be it.

[mdtritn21]

Measure it like this http://www.bbcboards.net/showthread.php?t=62660 If the concrete is level level the pad and the cav plate and set it. It will never have a real good hole shot with a 2.5 200 efi.