1998 xb2003 set up

**brotherxb03** · 03-01-2005, 01:31 PM

I have a xb2003 set up with a 2.5-200 mercury. It had 14" of setback which consist of a allison manual plate with a bob's hydralic 6" bolted to it. I have a 200 lower unit with a bob's sportsman kit on it with stock side holes pluged. I tried several props 25 tempest,24 edge,26 tx4 hydromotive,28 mercury chopper worked by hopkins. I also have the bob's fin on lower unit and sea star-pro hydralic steering. So here's the problem,the only props that runs decent is the 24 edge which will put the spedo @ 82 at 6850 rps. The tempest runs 80 @ 6800. The other props wont lift the boat unless i run the hydro plate around 2'' up frome bottom which is 3'' below the pad with prop shaft. And with the chopper all the way down and still won't lift the bow worth a toot. Also when i ran the hydromotive it did a 90 degree left turn @ 75 which caused me to put it on the trailer,go home and change my shorts. Does any one think it could be the bob's fin?. I"ve been driving bass boats for over 20 years which included a hydrostream varmit with 200 merc. Thanks for any help in advance Phil

**Ziemer** · 03-01-2005, 01:49 PM

I have a Grand Sport which is similar hull just different cap (not a bass boat)

Can you clarify where exactly you are running the propshaft in relation to the pad. If I read it correct you're running it 3" below the pad??? If so this is way too low. I have the 9" Allison jackplate and I run about 1/8"-1/4" below the pad.

One thing you will learn quick, is that no aother boat drives like an Allison. Out of the props you listed the Hydromotive wiil probably be the best option, either that or the chopper, although I have a chopper that's been worked by hopkins and it is not the best running prop on my boat.

Anyway, I would start by setting you motor around 1/2" below the pad and working up in 1/8" increments. Take your time and don't forget your life jacket. Left and/or right hand turns can be common in an Allison if you're not careful. I would guess if you have a pretty stout 200, your boat should run right at 90 or even a little better.

The fin on the cavitation plate should not affect you running because when your motor is set at the correct height it would be out of the water. You will probably find that you don't even need it.

**brotherxb03** · 03-01-2005, 07:18 PM

It seems like something isn't letting the water get to the prop and lift the boat as it should. I don't know if the bob's fin is deflecting water off the prop stoping the lift or water is deflecting off the top step on the transmon to a skid plate i had just on the bob's 6" plate. the reason this is like this is because I took the hydralic 6" along with the motor off my other boat. I took off this plate,but didn't run the boat yet. Also if I try and pick up the motor higher then around 1 1/2 inches below the pad I start to lose water pressure. Below this I have 25 psi at wot. I have water intakes on the top and bottom of the nose only.

**Ziemer** · 03-02-2005, 06:23 PM

I think I know what bob's cone you have because I think my last motor had the same one, it has intake holes above and below the cone. I think it was originally meant for bass boats that are frequently in the weeds, in case the lower holes are plugged, the upper ones will still flow.

Anyway, you probably won't get anymore speed at the height you're currently at. Also, you should be safe for water pressure as long as you don't go much below about 15 psi. (Experts correct me if I'm wrong)

You won't believe how much better that boat will handle with the motor up at least an 1" (which would put it about 1/2" below the pad). If you're running 82 now I would bet you would probably run almost 10 mph faster once you get the engine height dialed in.

**brotherxb03** · 03-02-2005, 06:46 PM

I only tried runing the hydromotive tx4 prop once and when I first took off I set the engine height about even with the pad and found their was little to no bow lift but didn't run it long at this height due to 6 psi water pressure. Then I droped It down to about 2" below the pad had a little too much bow lift and 25 psi water pressure and thats when it blew out and spun left. So I will try blocking top inlets on nose cone,Phil

**TB21** · 03-02-2005, 09:23 PM

Opposite of what most think , that T4X prop has no bow lifting ability , its a tail lifter . I have a 28 T4X i bought for lifting a bass tournament load and its the worst prop i've seen for bow lift. TB

**Ziemer** · 03-02-2005, 09:36 PM

Want to post this question over on AllisonOwners.com also. I thought by now you would have had more responses. I know there is a bunch of guys over there with your same boat and a few with your same motor.

www.allisonowners.com

Good luck.

**Jimbo** · 03-03-2005, 01:13 PM

There may be a simple explanation for your problems. ( this is just my opinion )

Is it possible you are over trimming? If the prop loses its bite; the bow on an Allison will drop and the boat will hook or spin around.

I would try to get an Allison owner or dealer near you to look at the boat. There could be a problem with your jack plate, gear case, or hull pad.

I say this as an Allison owner that has run 1/2 inch above the pad with a 26 inch merc chopper and 28 inch Hydromotive quad 4 O/T and still had 20 PSI of water pressure. My gear case is a Merc CLE with Bob's cone, torque tab, and blow out ring.

Most Allison owners with 14 inches of setback can run from 1/4 inch below the pad to 1/4 inch above the pad with good speed and none of the problems you are having.

Good luck in finding the problem. You have a 90 MPH boat there when you solve the puzzle.

Jim

**TBuck2003** · 03-03-2005, 01:55 PM

Hey for what its worth I think I can help you with your scenario.First of all the T-4x is not going to be your prop for a fishing load it is primarily a go fast weekend warrior prop.It was never designed or intended for that purpose.We have had alot of success with the Quad IV ot on your same boat.Have personally worked on 50 plus 2003s so I know the boat very well.I have a xs 2003 that we prop test with all the time.27-28pitch 1/4" below pad should put you in the ballpark.Please feel free to call me anytime to discuss your particular scenario.Would enjoy working with you to get your rig squared away.

Todd
330-425-3629

**RB in NM** · 03-03-2005, 02:10 PM

I got a xb03 with 14.5 inches of setback, w/15"2.5 merc. Your setback is about as common as it gets for the xb-2003's. As already mentioned you need to find out exactly where your propshaft is in relation to the pad. I have hydl. jackplate setup so that when all the way down, it's 1/4" below the pad.
You will have a "drag" effect and ill handleing with the prop buried too deep at speed. I think you pointed that out and are correct with your assumption.
You will be amazed the difference when you are able to run it a even 1/2" below the pad, that's the most common starting point, 1/2" below.

One thing you have mentioned that scares me is that Bob's Sportsmans Nose cone. That cone is designed for heavier hulls that have to run the propshaft 3-4 inches below the pad. With those additional holes located on the top of the cone, you can run that puppy outta water in a hurry, if you are running closer to the pad. I would ditch that nose cone for the Bob's low water Pick up or an equal, but make it a low water pickup. Whatever you do, please run with an operating water pressure guage with that sportsman cone !
Heat kills...

Get onto the Alli site, you'll find a lot of good info and help there as well.

Good luck, Russ

**TB21** · 03-03-2005, 03:23 PM

Hi Todd,
At the 03 Rumble you told me for my xb2002 the T4X would be a great load carrying prop so i bought one and its performance is very dissapointing loaded or light. Only reason i havent called is because i didnt buy it from you , but it was same as new couldnt tell it was run. At the same time you told my buddy that the Quad IV would be good for his xb2003 so he bought a new one from you , and it is one of the most impressive props i've bolted on , it will flat out lift and fly on my 02 , i sure wish you'd recomended that one to me before i bought this T4X. TB

**1ally** · 03-19-2005, 12:23 AM

Allison setup
Todd i saw that u do alot of testing with allisons.I have an xb03 with a merc. 260 15" mid section,sportmaster lower unit(stock),and a 30"E.T. prop. set at 1/8" above the pad.The boat handles great,but I experiece a problem at speed (102) the bow tends to drop or actually feels as if it is being pulled down.When it starts to do this i can bump the trim and maintain positive bow angle.Is there any truth to what is said about the lower unit that i am running about not able to run speeds above 100 without mods,or could there be something else causing my problems.If it helps to know i called Merc racing give them my info and they said that my prop needed cup removed from one area of the blade and added to another area of the blade.Did that and have the same results!!!!!!

**catfish123** · 03-19-2005, 06:58 AM

On that 30 ET, where did Merc tell you to take off cup and add cup??? Thanks

**1ally** · 03-20-2005, 03:49 PM

catfish,sorry it took so long to return your mesg.Cup was removed from the leading edge and added to the last half of the trailing edge.The boat lifts great with minimal pos. trim.just have this exp. at high speeds. I have never run any other prop designs for high speed.

**brotherxb03** · 03-25-2005, 10:11 PM

I removed my Bob's fin and skidplate on 6"bob's amd marked indicator on plate for propshaft center even wtih pad. I went fishing by my lonesome with my 28 chopper.Boat handled good going across the lake,2 ft chop 65 mph @5 grand.
Didn't open it up though,wanted to be in wide open area incase of bat turn. The boat acted good,respossive to trim,just when I thought I had it licked I made a turn off the main canal on the game reserve at about 55 mph and the v on the front must have grabed and had to fight not to loose it. IF Someone would have seen me they would have sworn I was a drunk rookie. These allison xb2003 boats are a trip.
The good news is I caught my limit of bass for a fish fry and released around 12 more. Also I ran into a guy at the lanch with a STV who also own an ali 2002 and he said his friend ha a 2003 and these boats were the hardest to drive of the ali's and had to be set up perfect