PROPSHAFT HEIGHT

[chad202]

What is it that makes so many run a XB03/225 at 1/4" below the pad. Is it the handling, speed, load carrying ability, scared to blowout? Since owning my boat( which has only been a few month), I've set it up to run even with the pad. Have any of you actually went from even to 1/4" below and picked up speed? Where was handling better? I know the only way to truely find out is to do it but just thought ya'lls experience would be helpful. I was actuall thinking about going up a 1/4" instead of down. The boat has had no sign of blowout and I have released the throttle a good bit several times and it just sits down smooth. The boat handles great at current height. I don't get the lift I would like at cruising speeds but I think that is prop and not height. Oh, my pad was blueprinted at the Allison factory so I don't know if that changes anything. My % slip when running is only 5%. The boat literally almost drives itself. Thanks for the help. I am truely loving this boat and have already told all who have asked what my next boat will be and my response is: I will never own anything but an Ally.

 

[jay j]

height

chad from what i have learned is that you can run these above the bottom
i have a grand sport and i can run it light loaded about a 1/4'' above. it all
depends on what you are gonna do. if you increase your height and it handles fine then i would say that its alright. if you get to a point to when you stab the throttle and it pushes the nose down its to high and will become flighty and hard to control. also with the 225 the motor will "peter"
out and cause a little drop in the bow so having the motor a little deeper
will help that. i had a xb-2002 comp with a 225ss and the sweet spot on it was about 1/8" below. i fished tournaments(24 gal gas 2 men 220lb+
fully loaded 27 srx 90.9mph) raced odba 1/4 mile and left the motor where it was at. i had a 12" jackplate. my grandsport has a detweiler 12"
hydraulic so i can play with it. so a happy medium is what you are looking for. prop selection , weight distribution, and intended use has everything
to do with the equation. they are some of these finest if not the finest
sport boats you can buy. the fun factor considered, these boats are on top
i have had an stv tunnel, triad v-bottom, and two allys one blazer and they are all fun if it is want you want it to be. the allys let you have your cake and it too. hope this helps, have fun

 

[JOEALLY]

Chad,
I was wondering the same thing. I'm running mine at 1/4" below the back lip of the pad. So it seems to me that the lip is about 1/4" 'sticking down' below the actual pad. So does this mean I'm running even with the pad or do most measure to the bottom of the lip and call that the pad?

 

[catfish123]

Chad----------I believe you will find most people who have your boat, motor combination to be running around 1/4" below the pad. Yes, there are some who claim to run higher without problems but they are in the minority. Getting an accurate measurement to within 1/4" is not easy either because of the many variables. The higher you go, the more likely you will experience blowout and all the "fun" that goes with it. You have to decide at some point the risk to reward relationship of trying to get that last mph out of it. I have found the gains in running much higher than 1/4" below the pad to be very slight and not worth the risk.

 

[GotMyAlly]

I ran up to 3/8" or 1/2" (can't remember exactly) above with my Trophy. It slipped a lot in the mid range but accelerated great on the upper end (for a trophy) and got to the limiter quick BUT it ran out of water pressure. That was with one person, light fishing load, full gas tank. Don't know how it would have ran up there with two people. The trophy (that handled like crap on my boat) handled the best at those motor heights. I'm running 1/4" below with my 28" hydromotive now, but have not seen any reason to go up (I can already hit the rev limiter with 2 aboard). When I start prop testing again, I want to try some 30" props and I may go up to even then if needed to get the rpms up. But for carrying a fishing load and running in rough water, 1/4" below works well for me.

 

[chad202]

Joe if you measured from the very back of the pad, you are probably around even with the pad. I measured mine about 4-6" up from the lip and it's 1/8 below to even.

 

[deadeye99]

motor height

I have a hydraulic plate and 9 years with my xb2003. You can run higher but at each increment the boat gets a little more "squirrly" and on mine at least there is no gain in speed. If each .25 inch went faster fine, but with no increase in speed why push it? I have run as high as 1.5" above. Even to .25 below is perfect. Bob

 

[chad202]

Thanks. I'll leave it at even and maybe go down someday. It handles great at current setting.

 

[merc326]

you will be fine at even with the pad, and when you get a wild hair, go up to 1/4 and try it, you will find it gets even easer to run at higher speeds and have even more mid, i ran my xb2002 at 1/2 above for a long time but when i went to a 28 et it seemed to handle a little funny at around 100 so i dropped it down to 1/4 above and its awsome. just be careful when you try it, like you said just run it up slowly and be on the look out for sighns of instability in the arse end, i personally think you will be fine but im not the one who will be driving it either. just be careful. you need to come down on the 29th, put off what you have to do man, we will play around with that thing bud. come on. please..

 

[froggy]

Engine Height

Chad,

My buddy, who also has an XB2003, runs best at 1/8" below the pad when he's light (fuel, 3 batteries, troll motor and driver only). With a fishing load he needs to drop the height another 1/8" so he's at 1/4" below the pad. The lip on his boat is .090". I mentioned him because his XB 2003 is powered with a 225 ProMax.

I am running 1.25" above the pad and still have great lift and the ability to trim way too much and still have prop bite and water pressure. As soon as I raise my manual plate, I'm going to go higher until I lose either prop bite or water pressure. At my current height, I have a little 'surging' at one point in the mid range if I trim faster than the boat's attitude can catch up when I have a full fishing load. The lip on my pad is .060". I run a 280 on my XB 2003. I am still experimenting since my gearcase was modded recently by Titus Grisham. I could not run these heights when my sportmaster was stock. I am running a 280.

It seems that the best and sweetest spot for most XB 2003's is at even to 1/4" below, I don't understand why mine doesn't like it there!

Just keep it safe when you are going high. I run my boat, when I go higher, by overtrimming at slow speed, say 50MPH, and making the boat 'prop walk". At the point when the boat prop walks, I look at my trim gauge (stainless marine), note the position, and mentally never allow myself to trim that high when running for top speed. So far this procedure has kept me out of serious trouble.

Joe Ally, when you are running even with the lip, you are likely .090 to .100" below the pad.

I hope this helps.

froggy

 

[ziemer]

Gearcase?

The height and handling also depend on which gearcase you're running. The sportmasters usually are run a little lower than say a coned stock case.

 

[chad202]

I'm running a torquemaster with Tooters nosecone. Stock torquetab on skeg, no mods.

 

[brotherxb03]

I think it also depends on the prop yoy are running. When I run my choppers and can run even to 1/2 above. When I run my 25 tempest I need to run at least 1/4 below the pad. I run a stock 200 lower unit with a bob's sportsman.