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Request for Compatible Gears for Honda 650 Engines XR650L, NX650, FMX650, etc

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I am wanting to create a wide ratio gearing for my XR650L and trying to learn if there is a Honda OEM stock first gear from any Honda 650 engine that is compatible with the XR650L that is one tooth more than the XR650L stock 1st gear.

What I'm trying to do is get the ratio to something like 33/12 - 2.75 or 32/11 - 2.91. I'm researching if there exists a gear or gear pairing that will accomplish this.

Is there a compatible Honda 650 transmission that would drop into the XR650L transmission and give me the gearing ratio preferably close to a 32/11 - 2.91?

I have already obtained the 2nd and 5th gear listed on this thread.
http://www.advrider.com/forums/showthread.php?t=649249

My thought is if I am going to crack the case open then I might as well get all the gearing I want.

Any help would be greatly appreciated.

Gearbox Operation
http://www.justxr.com/jaw/gearbox.html

The 1st gear is #4 on the parts fiche.

 
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hey TJROCKET that's a big project.! spliting the case's and all..you mite want to ask the guy's on ADV-rider for better info on swapping out gear's in the tranny.... good luck TJ. :rider:......lonnie.....
 
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Info from another thread.

There are two physical gears in each transmission "gear," so numerically higher or lower than ___?

So #4 in fiche, XR650L OEM stock gear has 32 teeth. I looked at the XR600 OEM since it is 31 teeth and I was told that is the wrong direction and that I need a 33 tooth gear. Not sure if it exists.

I'm guessing #10 in the fiche is the matching gear to #4 which is 20 teeth so if 21 teeth accomplishes the same thing and works, then I'm all for it.

Do either exists?
 
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You do realize you can't just change one gear to get what you want? You must change the matching gear on the other shaft. Iset out to do this on my race bike and found it to be costly as geat sets often run in excess of $500.

Just a thought.
 
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You do realize you can't just change one gear to get what you want? You must change the matching gear on the other shaft. Iset out to do this on my race bike and found it to be costly as geat sets often run in excess of $500.

Just a thought.

From what I've read, lots of guys have been successful only changing the one gear. This topic seems to always come up and the guys that have done the mod swear that you don't need the matching gear.

But obvious, a good tip!!
 
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Info from another thread.



So #4 in fiche, XR650L OEM stock gear has 32 teeth. I looked at the XR600 OEM since it is 31 teeth and I was told that is the wrong direction and that I need a 33 tooth gear. Not sure if it exists.

I'm guessing #10 in the fiche is the matching gear to #4 which is 20 teeth so if 21 teeth accomplishes the same thing and works, then I'm all for it.

Do either exists?

If my thinking is right(sometimes it is) the #4 would have to be a bigger gear(more teeth) to get a higher gear(less rpm at same speed) since it would be the same as going up or down a tooth on the drive sprocket.

I dont see how changing only one gear could work since the more teeth it has the bigger the gear has to be physically. You would run out of room since the offset between the gears is a fixed variable. If it is only one tooth you might be able to squeeze it in since the size wouldnt change much. Im sure it would probly wear out quicker and might whine from meshing of the gears being to close. I would stay away from going any smaller with any gears without having a matching counter gear though. It might start "jumping" and could break off the end of a tooth...

Why dont you look for a complete transmission that you could swap out instead of just a couple gears? There has to be different models that have different ratios.
 
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I dont see how changing only one gear could work since the more teeth it has the bigger the gear has to be physically. You would run out of room since the offset between the gears is a fixed variable. If it is only one tooth you might be able to squeeze it in since the size wouldnt change much. Im sure it would probly wear out quicker and might whine from meshing of the gears being to close. I would stay away from going any smaller with any gears without having a matching counter gear though. It might start "jumping" and could break off the end of a tooth...

This is a compatible Honda 650 engine. Honda designed the gear to work so that the teeth are compatible. Again, several guys have done this over the years with no issues.

1993-1999 NX650 & FMX650
32/12 2.66
28/16 1.75
25/20 1.25
23/23 1.00
20/25 0.80

XR650L
32/12 2.66
28/17 1.65
25/20 1.25
23/23 1.00
21/25 0.84
 
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