I really need some help from the experts if possible.

Boat - 1994 Astro FSX20 Fish n Ski (21')
Engine - 1994 BlackMax 200 efi
Props: (3 tested)

Manual recommended WOT = 5250-5750rpm

1. Tempest 48-825864 A45 23p , SS 3 blade (think it has been worked on.)
2. Trophy 48-825942 25p , SS 4 blade
3. Aluminum - 48-832832-C1 21p , alum 3 blade

So my problem is that I am getting really bad performance. It it very poor on holeshot and when I am fully loaded I can barely get on plane. In tight turns it seems to "slip" and i have to back off throttle and let it "catch" up. When I initially take off, the holeshot "slips" a lot also and I have to gradually throttle up to speed. I tested all 3 props today with a normal load and the results are:

Tempest 23p = Slow, gradual holeshot to plane. WOT=5300, top speed = 58mph(gps)

Trophy 25p = seems like very poor holeshot. WOT=5300, top speed=54mph (gps)

Aluminum 21p = Real good holeshot. WOT=6000, top speed=54mph (gps)

The 2 SS props are vented props but I have no plugs for them. The Tempest was apparently vented by previous owner and I cant buy plugs. I dont know if the Trophy is worth keeping so I have not invested in that one. My engine mounting on transom has 4 holes. It is currently installed on second hole from top, so the motor can go down 1 more or up 2 more.

I just want good solid performance that I am not constantly having to mess with. it is making it difficult to enjoy my toy.

I appreciate any of your help, thx in advance.

Ok, first we need to take a truth pill, so your expectations are actually real.

Fish n skis will never run with regular bass hull, too much weight forward, so first you'll give up 5 mph or more because of that..

A 6" jack plate will make a world of difference, find one and install, anything BUT a rite hite...

Your tempest will be the best choice for all around performance,

get a handfull of PVS plugs for it, so you can tune your holeshot. I'd guess to start two medium and a large.

Slipping around turns is the nature of that hull, no fix, just learn to control it.

Honestly 62 should be a reasonable expectation and that plate should do it.

Thank you for your response. I am not looking to "run" with Bass boats. I know it wont perform like those but I am having really poor performance in general and just want to correct the problem.
I understand it is a lot of trial and error, but I wanted to avoid some frustration and expense by asking here.
I am not looking for extreme top speed so I am willing to loose some of that for good holeshot and a solid running motor.
I will look into the jackplate and see if that will fit within my budget.

Thank you again,

Also if your planning on pulling a skier then you will probably need to drop a little in pitch. Most of the water sports time is spent in the heat of the summer when your motors performance is at it's worst.

See if you can try a few props for free. Save the jackplate money and just take your time to find the right prop. Check out a 4 blade in a 21 or 22 P.

i work on them and i would recommend checking the flo torq hub. sometimes the hub can slip even though you might not have hit something .sometimes they just crack. if your 21p aluminum works best then u you should go with that.mormally u would go down 1 or 2 pitches if oyu want to go stainless but with hte blackk max u can use 21p ss .i would definitely get some vent plugs

i have a 21p turbo TXP 3 blade. come out to lake fork and test it before buying.

Thank you all again for responding.
When I look at the numbers i am getting 6000rpm WOT with the 21p Aluminum. I guess for what I have tested that is my best performer but is 6000rpm too high? The engine is rated 5250-5750.

6k is too high for this time of year. i'd prefer 5600 in the heat and 5800 in cooler weather.

I just measured my motor height and it is currently sitting 5 1/2" below pad right now. How does that effect my performance as above? Should I raise it up 2 notches which should put it close to 3 1/2" below?

1" at a time.

1 notch at a time.

+1

Steve can add some cup also to help with the RPM's if needed and go up 1 hole on the mount. The aluminum may be blowing out is why your getting the high RPM, that should be helped by a stainless with more rake.