Page 1 of 6 123 ... LastLast
Results 1 to 20 of 103
  1. #1
    Member
    Join Date
    Feb 2006
    Location
    Tazewell Tn.
    Posts
    2,614

    Allison xb2003/225 promax/sportmaster.

    Ok guys I just want to put this out here as a this is what it was, what I did to it and how it is kinda thing.
    I have a 1995 xb2003 with a 1995 merc promax. The lower went out last week so I have been researching info on lowers and for sale adds.
    Let's start with how it did. It has a 9" jack plate and the prop to pad was 1/4" below. I've had it 85 with a 25 trophy for a brief moment when I was learning to drive it, late winter. I have ran 82 for a while with a 27 and 28 trophy.
    Now since the lower went out I done some trading and got a sporty that came from the allison plant, blunted nose, allison cut skeg, torque tab in skeg and 1.75 gears. Ran the boat yesterday and it didn't do so well. When I got home I messaged a buddy that has a grand sport and got his specs and basically copied them. I added a 2" spacer to the plate for 11" of setback,leveled the boat, prop and raised the motor to 1/4" above pad.
    Went to the lake this morning to try it out, now mind you I am a little worried about being above pad so it took a minute to get up to speed. So out of the hole is kinda slow but not terrible, accelerates ok and handles a lot different. Yesterday I had to go way into positive trim to reach 70. Today I could do 70 at neutral trim and a bump into positive trim it accelerated fast to 75.
    I am looking forward to trying it out again with some good water. A few things I noticed, 1) it doesn't blow out before planning off anymore, I don't have to feather the gas pedal. 2) I think it's throwing a bigger rooster tail ( wasted energy). 3) At one point I was doing 70 mph at 5600 rpm's.
    It's like learning my boat all over again.

  2. Member
    Join Date
    Nov 2014
    Location
    TN
    Posts
    219
    #2
    How much lip is on your boat? What do you think of those gears so far? Not a lot of guys have them in the little motors. Interesting to see how it goes once you get it dialed in.

  3. Member
    Join Date
    Feb 2006
    Location
    Tazewell Tn.
    Posts
    2,614
    #3
    It's still got lip, I really wish it didn't.

  4. Banned
    Join Date
    Jun 2020
    Location
    Orange Beach, AL
    Posts
    583
    #4
    What prop are you running? That gearcase shouldn't make it that difficult to drive.

    Most folks run 14" setback on XB03's. At 9", you're probably going to have to be a little lower on motor height (water rises as it comes off the back of the pad).

    I always found trying to copy somebody else's setup to be nothing but frustrating. Every boat/ gearcase/prop is a little different. The best anybody else can offer is a general guideline. Especially an XB to GS..... same hull but weight and aerodynamics are very different.

  5. Member
    Join Date
    Feb 2006
    Location
    Tazewell Tn.
    Posts
    2,614
    #5
    I took all 4 plugs out of the 25 trophy and put a jack plate "skid planner " on. The boat got up on mich better and mid range was a whole lot better. Ran up to 80, well 79.9 was the highest speed I saw today and I didn't really have to "drive" the boat until I got above 75. Water wasn't the best either. One thing I'm not liking is the rooster tail that is to tall. I usually have a 2 to 3 ' one now it's a 4 to 5' one. All in all I like the way it's running, I think I'm not to fond of 11" setback.

  6. Banned
    Join Date
    Jun 2020
    Location
    Orange Beach, AL
    Posts
    583
    #6
    You ought to be able to run well into the 90s with a different prop

  7. Member
    Join Date
    Jun 2008
    Location
    Harriman, TN
    Posts
    528
    #7
    Don't worry about the lip. Now that you have it setup closer to what everybody else runs you need to get some seat time on good water. The 1.75 gears make the props act like they are 2" more pitch than with the 1.87 gears.

    The rooster tail is more important at wide open or close to it. Maybe go to even with the pad. The half inch you moved it is a lot.
    It will run OK with 11". Until you master what you have you won't be able to tell the difference.

  8. Member
    Join Date
    Feb 2006
    Location
    Tazewell Tn.
    Posts
    2,614
    #8
    After thinking about this set up for a while I do believe that I was at 1/2" below pad before. So yeah it might take a little seat time to get used to raising it 3/4".

  9. Member
    Join Date
    Feb 2008
    Location
    Living the good life on Lake Hartwell, Fair Play, SC
    Posts
    6,909
    #9
    something does not sound right. If it's a 2.5 liter (which it is) the original gearcase (the one you had on it)was 1.87 gears (unless someone changed it out before you owned the motor). Back in the early 80's Merc made a 150XR4 with a geacase that was a small hub 1.73 gears; I owned one. But ou stated it was a sportmaster so it had to be 1.87 gears.

    So you bought a "sporty" from Allison (are you absolutely certain it is a sportmaster?) because I'm pretty certain 2.5 liter sporty's were not made with 1.75 gears. I'm not even certain what all gears were made with the older CLE gearcases which I know Allison used and tested with before the sportmaster.

    I'll stop there before I "put my foot in my mouth" with incorrect ifo.

    How about some pics of these gearcases?? The original sportmaster should be stamped on the top of the case near the water impellar.
    2013 Allison XB-21 BasSport Pro
    2023 Mercury Racing 300R
    Bravo FS 30P
    ProMax 30P

  10. Member
    Join Date
    Feb 2008
    Location
    Living the good life on Lake Hartwell, Fair Play, SC
    Posts
    6,909
    #10
    another thing I was thinking.....I ran a 225 PM on my first XB21 2+2 and ran 28P props at 6400 RPM's in the upper 80's. That 25P you ran 85MPH should have had you on the limiter?
    2013 Allison XB-21 BasSport Pro
    2023 Mercury Racing 300R
    Bravo FS 30P
    ProMax 30P

  11. Banned
    Join Date
    Jun 2020
    Location
    Orange Beach, AL
    Posts
    583
    #11
    1.75 geared 2.5L sporties weren't all that common, but it was an option.

  12. Member
    Join Date
    Feb 2006
    Location
    Tazewell Tn.
    Posts
    2,614
    #12
    I got it from the guy that built my engine. He bought it from Darris last November along with another unit and a 200 merc. It looks like a sportmaster to me, and Randy. I emailed Darris and he confirmed everything the Randy told me. So I'm just hoping those two guys know what they're talking about. As far as going 85 with a 25 trophy and 1.87 gears, my limiter has been raised to 7500rpm and I'm just going with the speed that my GPS shows me.
    Last edited by big_o_tom; 07-07-2020 at 01:00 PM.

  13. Banned
    Join Date
    Jun 2020
    Location
    Orange Beach, AL
    Posts
    583
    #13
    Your holeshot should be great with a 25". Trophy is kind of the volkswagon of props, though.

  14. Member
    Join Date
    Feb 2006
    Location
    Tazewell Tn.
    Posts
    2,614
    #14
    It's not to bad now after I removed the 4 plugs.

  15. Member
    Join Date
    Nov 2014
    Location
    TN
    Posts
    219
    #15
    Quote Originally Posted by AllyFishing View Post
    something does not sound right. If it's a 2.5 liter (which it is) the original gearcase (the one you had on it)was 1.87 gears (unless someone changed it out before you owned the motor). Back in the early 80's Merc made a 150XR4 with a geacase that was a small hub 1.73 gears; I owned one. But ou stated it was a sportmaster so it had to be 1.87 gears.

    So you bought a "sporty" from Allison (are you absolutely certain it is a sportmaster?) because I'm pretty certain 2.5 liter sporty's were not made with 1.75 gears. I'm not even certain what all gears were made with the older CLE gearcases which I know Allison used and tested with before the sportmaster.

    I'll stop there before I "put my foot in my mouth" with incorrect ifo.

    How about some pics of these gearcases?? The original sportmaster should be stamped on the top of the case near the water impellar.
    You can put just about any gears you want in any case.

  16. Member
    Join Date
    Nov 2014
    Location
    TN
    Posts
    219
    #16
    Quote Originally Posted by Ditch_Pickle View Post
    Your holeshot should be great with a 25". Trophy is kind of the volkswagon of props, though.
    A good trophy is just about all you need the majority of the time.

  17. Member
    Join Date
    Feb 2006
    Location
    Tazewell Tn.
    Posts
    2,614
    #17
    I would post some pics of the gear cases but you know how that is...

  18. Banned
    Join Date
    Jun 2020
    Location
    Orange Beach, AL
    Posts
    583
    #18
    Quote Originally Posted by revlimiter View Post
    A good trophy is just about all you need the majority of the time.
    We'll have to agree to disagree there. That's like putting tractor tires on a Corvette. I wouldn't run a trophy if you gave it to me free. Well, I might put it on my aluminum boat to run through timber and shell beds.

  19. Member
    Join Date
    Feb 2006
    Location
    Tazewell Tn.
    Posts
    2,614
    #19
    I got a buddy with a promax that I'm hoping to try soon. Trophies are all I've ran on my allison. I traded a 27 trophy one time for a 28 chopper. That didn't work out to good, first time out with it and slung a blade at 60 mph.

  20. Member
    Join Date
    Feb 2006
    Location
    Tazewell Tn.
    Posts
    2,614
    #20
    Fixing to go try it out again. Hope the water is good.

Page 1 of 6 123 ... LastLast