Allison XB2003 with new sportsmaster lower unit, please help

**Ccazes** · 07-25-2015, 03:39 PM

I have a Allison XB2003 with a modified 1996 200 EFI Pro max and recently destroyed all of the gears and shaft on my Torquemaster lower unit with Bobs Nose Cone so I Purchased a 1999 225 Pro Max that has a burned #4 Piston and has a Sportsmaster lower unit. While I'm getting the 225 PM motor worked on I put the Sportsmaster lower unit on my 200 PM and it scared the **** out of me!!!!! Low bow lift and very sketchy at high speeds. Why is it doing this, should I stay with the torquemaster?

**Ccazes** · 07-25-2015, 03:46 PM

Oh yea, I've owned the boat for 15 years. I'm used to the boat and running high speeds.

**myron** · 07-25-2015, 05:35 PM

where is the prop shaft in relation to the pad, and how much setback are you running? A stock sportmaster can run well but it has to be set up right

**Ccazes** · 07-25-2015, 06:00 PM

The prop is 1 1/4" below the pad and I have 13" of set back. The boat was light, I pulled the trolling motor and fishing batteries to see how much faster the SM was vs. the TM. I was running a 26 chopper. This set up ran flawless with the TM lower unit.

**catfish123** · 07-25-2015, 06:37 PM

That sounds very low to me. I would raise the motor up to 1/2" below the pad and try it there. You may be able to go up even a little higher than that but I would try the 1/2" below the pad first.

**Ccazes** · 07-25-2015, 07:20 PM

I have zero lift now, wouldn't raising the motor make it worse? This same setup with the torquemaster would raise the bow so high I could barely see the water. I'm confused

**whipper** · 07-25-2015, 08:16 PM

Raising the motor will provide more lift and make the hull run on the pad better. At 1 1/2 below you have to much drag on the gearcase for fast running on a pad vee. The hull is designed to run 1/2 inch bellow to even with the pad. You start running lower than that with a chopper that is also designed to run half in half out of the water your going to feel all sorts of strange and wonderful things.

The hull has lift built into her. your not relying on the trim for lift but the pad to get the right angle of attach. The trim at speed should be around neutral to very slightly positive. So if you are buried below an inch below its not going to feel good at all. Been there hated that also. With 13 inch setback you will be able to run probably slightly above the pad but stick to 1/2 or even 1/4 below for now untill you get used to the SM. They do have a beefy skeg compared to the TM. Also some guys even get the allison cut to the skeg. But lots of guys run them stock so you should be fine. also taking the Troller off if heard guys say it makes the bow flighty? i dont have first hand experience with this but have read lots about this being the case with the 03. My hull is the same as yours though. The XS and XB03 are the same pretty much as far as driving. Listen to Catfish and myron they are very fast XB03 drivers with tons of experience running 100+. they know there stuff!

**catfish123** · 07-25-2015, 08:18 PM

Have you run the 26 Chopper before? I can only tell you that you are running the Sportmaster very low. Most people with your setup are about 1/4" below to even with the pad. If it doesn't run right around 1/4" to 1/2" below, you have another issue. If you get the motor too high, it can affect lift but at 1 1/4" below, you have a long way before you would get there.

**Ccazes** · 07-25-2015, 08:50 PM

Thanks for info, I'm kinda imbarassed to ask this. The measurement should be the difference between the center of prop shaft and the lowest part of the boat right?

**Ccazes** · 07-25-2015, 09:39 PM

I don't think I used my words correctly. What I meant was do I measure the shaft with the motor level or slightly elevated as it would be running to take my measurement?

**whipper** · 07-26-2015, 02:58 AM

Originally Posted by Ccazes

I don't think I used my words correctly. What I meant was do I measure the shaft with the motor level or slightly elevated as it would be running to take my measurement?

Hears an easy way. Make sure the ground is known level? Most garages have a 1 inch or more slope back to front but thats OK. Try and level the hull on the trailer with the trailer jack best ya can. take the level and put it on the rub rail on the wing the frame of the trailer fenders ect. Just do that best ya can.Then put the level about 6inches infront of the pad also check there. With cowl off trim the motor untill the level is level on the top of the flywheel. That is neutral trim. If you have a trim gage also a good time to mark it so ya know were neutral is on the gage. Take a measurement from the CENTER of the propshaft to the ground. Then from the pad to the ground. The difference is your engine hight above or below. if prop shaft to ground is 10 inches and Pad to ground is 10 1/4 inches your 1/4 below. mark 1/4 below,even and 3/4 below. You can mark 1/4 above but thats pushing it. if ya know were even and 1/4 below are those two are your best settings for speed runs and safest. Not sure on SM but i know on my case at neutral trim the bullet nose is also the same as the prop shaft hight. its trickyer than one thinks to get it right!!!! Ive measure lots of times and it seems every time im very close but a little different? Any way this is the way most do it. You can take the pad measurement just inside the lip or at the lip? Its only 50 or 60 thousands difference. if you get it to 1/4 below from 1 1/2 inches below your going to see a hudge difference in speed,Acceleration and steering input so not a big deal for now... have fun and be safe

**Ccazes** · 07-26-2015, 07:20 AM

Thanks again for taking your time to help me out, going raise my motor now and hit the bayou to see what she will do.

**texasvector** · 07-26-2015, 09:45 PM

well?????

**Ccazes** · 07-26-2015, 10:04 PM

Thanks for all the help guys, raising the motor even with the pad made a world of difference to the lift and handling. However raising the elevation also raised my RPM's while using the chopper. Before with the torque master I was turning 6600 with a light load. Today I shut her down at 7100.

**whipper** · 07-26-2015, 11:52 PM

Originally Posted by Ccazes

Thanks for all the help guys, raising the motor even with the pad made a world of difference to the lift and handling. However raising the elevation also raised my RPM's while using the chopper. Before with the torque master I was turning 6600 with a light load. Today I shut her down at 7100.

Then thats a good thing!!