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Switching from 21's to 23's

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Old 02-08-2011, 05:28 PM
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Default Switching from 21's to 23's

I have a 94 29' Scarab,350's mags with alpha 1's counter rotating. The boat came to me with 14 1/4" x 21 turbo props. and it over revs (5400) I was told in the genral forum that Mirage plus 23's would be the ticket. I have found some used on ebay but nothing 14 1/4" mostly around 14 1/2". Will that make a differance ? Also should I go with a solid hub or rubber and are all 15 spline the same as my alphas ? ..thanks
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Old 02-08-2011, 06:21 PM
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Originally Posted by Scarab29
I have a 94 29' Scarab,350's mags with alpha 1's counter rotating. The boat came to me with 14 1/4" x 21 turbo props. and it over revs (5400) I was told in the genral forum that Mirage plus 23's would be the ticket. I have found some used on ebay but nothing 14 1/4" mostly around 14 1/2". Will that make a differance ? Also should I go with a solid hub or rubber and are all 15 spline the same as my alphas ? ..thanks
The rubber hub is fine for your setup. And yes, they will fit the alpha. The 23" Mirage+ is 14.5/8" in dia, and that is a perfect dia. for your boat. The larger dia. wil give you better bite and less slip. The 23" should put you at 67-68 mph @ 5000-5100 rpm's (that is with 8-10% slip). What kind of speed are you seeing now? GPS speed is needed.

Last edited by A.O. Razor; 02-08-2011 at 06:49 PM.
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Old 02-08-2011, 07:40 PM
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I have seen 63 mph.. Thanks
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Old 02-09-2011, 08:33 AM
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This is just my opinion...but I dont think he'll see 67-68 mph, but...I could be wrong. By the way...I have a nice set of 23 Mirages for sale if your interested. They are the standard...not the plus'es (did I spell that right ? lol).
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Old 02-09-2011, 03:28 PM
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Originally Posted by tinman565
plus'es (did I spell that right ? lol).
It's all good

About the 67-68. My thought was, that if he could swing a 21 at that rpm, and slip would go down with the M+, it could be around that. But 65-66 is prolly more realistic. Slip with the current 21's is 14%, and 23's with 12% slip, would be 65-66 @ 5000-5100 rpm's. Labbed M+ssess could be fun.

Last edited by A.O. Razor; 02-09-2011 at 03:52 PM.
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Old 02-09-2011, 04:01 PM
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Originally Posted by tinman565
This is just my opinion...but I dont think he'll see 67-68 mph, but...I could be wrong. By the way...I have a nice set of 23 Mirages for sale if your interested. They are the standard...not the plus'es (did I spell that right ? lol).
i would put the23 props on they are better then the plus . more top end and will be faster midranges. i have both props the plus did 2mph slower at top end on my boat.
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Old 02-09-2011, 08:34 PM
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there's a set of new mirage+s in the swap shop for 750
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Old 02-17-2011, 08:32 PM
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You won't turn the mirages. Laser 2 23's are the ticket. If you upgraded the power at all to like 320 + you might turn the mirages. I have the origional 270hp carb mags and run the 23 lasers on alphas 64-5 @ 4800. My bud has 96 29 w/ mpi mags and bravos and runs mirage + 23's 68-9 @ 5000 rpm.

Last edited by hunster; 02-17-2011 at 08:38 PM.
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Old 02-18-2011, 06:21 AM
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I am under the impression that I have 300hp motors, I am not positive about the 1 that I did not replace but I was told by the owner when I bought the boat that they were 300 each. one **** the bed right after I bought so I went with a brand new gm with roller lifters and was told by Michigan Motorz it would be 300hp. The motor that came out was also a roller motor
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