36% slip?
#1
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From: aurora, colorado
took my 2004 magic wizard out for the first time yesterday and only ran 61 mph. that was @ 5000 rpm with a bravo 4 blade 30p prop. any ideas on what i should do. 1.5 ratio xr drive with a sportmaster lower. it would run 55@ 4300. this was at 5400ft of elevation but i think it should still run better. i'm new to the performance boat thing so any help would be great. thx, Tony
#2
I calculate 31-34% slip at either elevation. Something is very wrong here. If these numbers are correct, you will be running a low 20's pitch propeller once the slip is harnessed.
What engine are you running and has the propeller ever been repaired or adjusted?
Brett
What engine are you running and has the propeller ever been repaired or adjusted?
Brett
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Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]
Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]
#3
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From: aurora, colorado
it has a 575sci with an intercooler pushing 8lbs of boost. i just bought the boat. it was a repo so i dont have any history. it looks like it has never been repaired but i really dont know.
#5
The elevation affects make sense and fall within the parameters of change. However, the performance is lack luster. From the little I know about this so far, it seems there may be engine and set up/propeller issues.
I'd try another propeller of smaller pitch and check the results.
Also, is the XR a shorty and how low below the boat bottom is the point of the gear case? Or is it above?
Brett
I'd try another propeller of smaller pitch and check the results.
Also, is the XR a shorty and how low below the boat bottom is the point of the gear case? Or is it above?
Brett
__________________
Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]
Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]
#6
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From: Spokane WA
My guess is that your x dim is way off. I bet that your drive is to high with the shorty. That is why you are spining a 30p at 5000 rpm and only going 61. What is the prop shaft from the bottom of the at now?? You could also try going to a 5 blade but I would guess with that much slip your drive is way to high. IMO Brett will get you going the right way he know his stuff.
#7
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From: aurora, colorado
The elevation affects make sense and fall within the parameters of change. However, the performance is lack luster. From the little I know about this so far, it seems there may be engine and set up/propeller issues.
I'd try another propeller of smaller pitch and check the results.
Also, is the XR a shorty and how low below the boat bottom is the point of the gear case? Or is it above?
Brett
I'd try another propeller of smaller pitch and check the results.
Also, is the XR a shorty and how low below the boat bottom is the point of the gear case? Or is it above?
Brett
#8
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Definitely a problem with setup and/or engine.
An overly high x-dimension could cause major slipage like you're seeing. 6-inches seems high for a Wizard. If you drop the hammer at, say 4000 rpm, are you seeing a quick spin up to 5k? Could be aerating your prop.
Can you double check your prop size?
#9
We had a nice conversation today and we have a game plan.
We'll wait to hear back on some possible water pick up issues. After that there is the propeller and then the engine and then back to the propeller. 1 step at a time.
CC, we are talking 6" below not above. This would be a conservative "X" dimention, not aggresive. Also, sci's are affected by elevation although not as severly as NA's.
Brett
We'll wait to hear back on some possible water pick up issues. After that there is the propeller and then the engine and then back to the propeller. 1 step at a time.
CC, we are talking 6" below not above. This would be a conservative "X" dimention, not aggresive. Also, sci's are affected by elevation although not as severly as NA's.
Brett
__________________
Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]
Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]



