Belt Redrive/Reduction help for Yamaha RX1 engine

Airboats with smaller powerplants.
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AlaskanOutdoorsman
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Re: Belt Redrive/Reduction help for Yamaha RX1 engine

Postby AlaskanOutdoorsman » Wed Aug 01, 2018 12:34 am

OneBFC wrote:axial load ratings would be one thing to check very carefully on the pillow block style reductions.

choose bearings wisely.


You are correct. The turbo belt drive setup was 200 HP at 9000 RPM. The builder used pillow block bearings and split lock collars up against the bearings to lock the shaft from pushing through the bearings. The builder told me that it was important to use spherical double row bearings in the pillow blocks. The ones he used were rated to 1200lbs for axial thrust (each) - the 70" Sensenich prop produces about 800 lbs. from what I was told. His bearings are larger than need be due to the driveshaft size that could be cut down saving weight.

Air canada
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Re: Belt Redrive/Reduction help for Yamaha RX1 engine

Postby Air canada » Tue Aug 21, 2018 11:15 pm

Thanks for the info gona try and make my own gear reduction this fall but by sounds of it the 4 cylinder will be smother than the 3 cylder
:canada:

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AlaskanOutdoorsman
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Re: Belt Redrive/Reduction help for Yamaha RX1 engine

Postby AlaskanOutdoorsman » Sat Aug 25, 2018 2:51 am

Yes sir. Based on conversations I've had the RX1 3 cyl will most likely need the addition of a harmonic dampner to address the vibration. That said, R1 motorcycle engines with the transmission in second gear can run direct drive without any additions but the engine is usually a few thousand more in costs (in my state) compared to the RX1.

Air canada
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Re: Belt Redrive/Reduction help for Yamaha RX1 engine

Postby Air canada » Sun Sep 09, 2018 9:17 pm

Do you happen to have the exact output shaft rpm in 2nd gear at wide open throttle for the r1 motorcycle engine ? That seems like the route of least Fabing ?
:canada:

Air canada
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Re: Belt Redrive/Reduction help for Yamaha RX1 engine

Postby Air canada » Mon Oct 01, 2018 7:03 pm

AlaskanOutdoorsman wrote:Yes sir. Based on conversations I've had the RX1 3 cyl will most likely need the addition of a harmonic dampner to address the vibration. That said, R1 motorcycle engines with the transmission in second gear can run direct drive without any additions but the engine is usually a few thousand more in costs (in my state) compared to the RX1.


Alaskaoutdoorsman second gear ratio in a 2005 Yamaha r1 is 2.065:1 so that divided by the max rpm witch is 12500 comes to propshaft speed of 6059rpm witch seems to fast for a prop speed if my math is right or does the prop bring max engine rpm down from 12500 rpm ? Even in first gear with the ratio is 2.533:1 witch comes out to 4934rpm prop shaft speed witch is still to fast so does the rest come down to pitch of prop to reduce wot rpm ?

Thanks in advance
:canada:

Muckduck
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Re: Belt Redrive/Reduction help for Yamaha RX1 engine

Postby Muckduck » Sat Oct 06, 2018 3:43 pm

If you check out my cbr 600 build there was a little bit of conversation about this. You want to get as close as you can with the engines transmission and then you can use a chain or belt drive to fine tune the ratio.

Air canada
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Re: Belt Redrive/Reduction help for Yamaha RX1 engine

Postby Air canada » Sun Oct 07, 2018 3:55 am

Muckduck wrote:If you check out my cbr 600 build there was a little bit of conversation about this. You want to get as close as you can with the engines transmission and then you can use a chain or belt drive to fine tune the ratio.

Ya I seen that checked out your build today looks awesome but what I'm trying to figure out now is I would of gone with r1 street bike engine if I could run direct drive off trans shaft of the the r1 in first or second gear but the numbers didn't seem right so leaned towards 2007 Yamaha apex efi and wana do belt redrive off that becuse going through r1 trans to another gear ruduction seems like more weight and why have two reductions when ya can have just one off crank ?
:canada:


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