wondering how my numbers and set compare to others with a xb2003 running a 225pm. Have not been around other Allisons to see. Just finished breaking the motor in from the rebuild (conneting rod bearing on #1 hole ). Ran it the other day with just me in boat gps showed 84mph turning a 27 pitch quad IV OT ,3/8 below lip (stock 94 model),11 inch total setback. tach showing 6100 to 6200 with it to the floor. Trimed about half way between level and full trim ,3 batteries, around 18 to 20 gallons of fuel, all my fishing stuff and cooler. Running a sporty now. Have seen 85 on gps before but had a coned t/m on then everything else set up about same other it was before rebuild around same rpms showing best remember. like to know if this in ball park or I need to do some changes. pretty sure loaded heavy compared to most. I think tach might be off a little on top end got to get another to see. Thanks.
How this compares to others
- Thread starter jcoats3
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whipper
Well-Known Member
Normal for the load and setup. 1/4 below and remove the limiter on the motor and turn a 25 the same speed only quicker. Turn a 26 at 1/4 bellow faster than 85 with a load. A 27 is good for gas milage at 50+ but on the tall side with a 225 with a load. You want to turn a prop closer to the stock limiter of 6750 than 6100. If you raise the motor to 1/4 blew you might get 200 or more rpm out of the 27 with a load also.
so sounds like pretty good were it setting, will be tweeking some. I am subject to 30 plus mile runs around here fishing so the gas milage is decent. between new sporty at end of last summer (skeg crack)and motor rebuild first this year got to walk softly by wife before bringing in some props :laughing already telling her need on for when we all on water with kids loaded down. Man i bought boat from said limiter was raised i think to 7500. test riding dont recall wathing for tach top reading, had a 25 pitch tempest on at time that had some extra cupping. I never got the hang of the boat before blade cracked on itfirst of last year that when got the quad IV. just found out about the limiter 4 months ago when he called me wanting to buy the boat back and was talking about the new prop and running. he had the boat since 1995 and 67yrs young when sold it.
Seat time is the key and small adjustments. Sometimes raising the motor requires moving weight left in the boat. Usually raising the motor requires less trim. 1/8" adjustment of the motor should yield 1-2 mph. Wear a good jacket and have a chase boat when testing new heights and trim angles you can never be too careful
GotMyAlly
Well-Known Member
Sounds like you need more setback. Most with XB03/225 combos run 14". Even more need for that if you're running heavy like you say.
Was the hydromotive worked or stock, and if worked, for an Allison?
Was the hydromotive worked or stock, and if worked, for an Allison?
GotMyAlly
Well-Known Member
You've got the right prop then. No reason that combo shouldn't bust 90. You should be able to spin to the rev limiter with the right setback and motor height.
TBuck2003
Moderator
Tach is probably off a bit... 3/8" below is about right for only 11" of set back. 14" is ideal on that rig with a motor height of 1/4" below pad. Keep me posted...
TBuck
TBuck
Just got back from doing some running and got some new numbers. I ordered a trail tech digital tach to use to check with my merc tach. Made a few runs around to see if tachs match watched them both up to 5500 holding merc tach steady. The digital tach bounced from 5550 to 5600. Made an all out run this time tach set on 6200. The recall showed 6400 max rpm on the digital tach. With that gps showed 87 max. This was trimmed fully up, boat picked up with every bump. Got out last week to remeasure everything and the prop shaft is 1/2 inch under the lip. Do y'all go from lip or up on pad itself on measuring? Had normal fishing load for day out but only 10 to12 gallons of fuel. Now it was around 90,92 degrees and humid in central Alabama today when I was out there.
hirk
Active Member
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Sounds perfect now, one thing to consider is your hull is a 1995 so the pad is about 2" farther back from the transom therefore an 11" plate is like a 13" on a post 1995 hull also if your running a center steer you wont want as much setback because your folcrum point will be further back when running with a passenger making it stern heaving compared to a side by side setup.Im setting my 1995 center steer up now myself.
patches
Well-Known Member
Do y'all really run the XB2003 motors that low? I'm a big opponent of extreme motor heights but that sounds very low.
I'm no pro but I think there are so many variations on how guys measure that it is hard to really compare apples to apples.
whipper
Well-Known Member
I was running threw a canal a couple of weeks ago and raised the motor all up so I didn't have to tilt the motor to much going threw because it was very shallow. Motors on the last hole as high as it can go on the jack. All up is 1 1/2 above or even a bit more if I recall? its great for trailering like this also with a 20 inch mid.
Any way after idling threw the lake on the other side was like glass!! 7:30 am. I punched it and was going 90 faster than I have ever felt before and was building speed in a real hurry. I noticed the hull seemed way higher out of the water than normal and steering super loose!! i realized holly crap I forgot to lower the motor to even!! i gently backed off and lowered the jack and trimmed in. I also could hear the motor louder and growling more.
The moral of this story is engine high or extreme hights make a huge difference. Ive explored 1inch above before but never floored it and ran way above an inch before. im not ready to explore this high any time soon as at 90 things didnt feel right. I could feel somthing about to happen. Blow out was at my door step. I was surprised I didnt blow out though I must say. I would have thought at just under 2 inches above i would have made it as far as I did. it was a good lesson. I think because I floored it and had my foot mashed the whole time it all happened so fast before I looked at the gauge all the way up!!:big grin After lowering the motor to even then going threw the gears back up to 90 it took way longer to finesse to get there than when the motor was way up.
I think 8 out of 10 Allison owner have there motors to low when looking for speed. But the more you go up the more aware of everything you need to be. Also when searching for ultimate top speed for the first time with new settings you should wear a helmet along with all other PSD. The frame of mind is important. You need to know that theres a great possibility something will go wrong. If your scared of what might happen you shouldn't try it! Leave the motor at even and be happy with those results.
I might after feeling it out were it's at might go up 1/8 to 1/4 inch more and run some. Were it's at carries the family pretty good just got to find smaller prop. To be honest most of the time around here mid to upper 70"s is faster then you need for traffic on lakes and the trash in the river. Still plan on as seat time and conditions come try to break 90 if can. I feel like set up right now is pretty safe can run a good chop without much fear in upper 70's. I will say the boat handled better and easier to drive when trimmed up all the way then trimmed down to just a click above neutral.
whipper
Well-Known Member
Thats a good plan when running with passengers. i will usually run no higher than 1/4 below with passengers. I had a 230 lb guy on my lap running even before could have been worse. Better safe than sorry.:beer: