How to make a KX500 billet extended clutch arm.

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Sandblaster
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How to make a KX500 billet extended clutch arm.

Post by Sandblaster » Wed Aug 08, 2012 3:44 pm

4-26-18 Latest information...
We no longer use the dimensions in these pictures and you should not either, except for over all lengths ect.
Why?
If you cut the 250/500 clutch puller arm off toward the top, you don't have to worry about grinding the welds.
And, if you have a quality welder (We do now) the welds look beautiful 8-)
So, use this info as a rough guideline...


How to make a KX500 billet extended clutch arm for an easier clutch pull.
It's no secret that the KX500 has amazing power and are great hill climb and desert bikes,
One of the complaints that we hear often is how hard it is to pull the clutch open.
I have to admit that after a long day of riding it can cause fatigue.
Since the bike was pulled from production in 2004, most after market manufactures no longer have much interest in coming out with new products.
What can a KX500 rider do?
Make your own!
First, let me give credit where it is due.
This was not my idea.
I originally found it on http://www.KXRIDERS.com which is a great source of KX500 information.
Here is what we are attempting to do.
We are using a stock KX500 Clutch arm, a YFZ450F billet Clutch arm from MOdQuad, and a stock YFZ450F clutch arm.
If everything works as planned this should give as a clutch arm that is 20% longer than stock.

Image

The plan is to use the bottom half of the KX500 clutch arm with the top half of the YFZ450F clutch arm and of course the Billet arm
If bikes are for kids I'll never grow up.

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Sandblaster
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Re: How to make a KX500 billet extended clutch arm.

Post by Sandblaster » Wed Aug 08, 2012 3:46 pm

Here is some views of the Billet arm:

Image

My first step was to make sure everything will fit:

Image

Everything appears to be perfect.
So, my next step was to cut the YFZ450F clutch arm to simulate how the whole assembly will fit, installed the Billet arm and slip it into the KX500 Case.

Image

Image

So far, so good.
I was surprised to see that the splines are not perpendicular to the arm but rather they are approximately 4 degrees out of square.

Image

Next, I ground the weld off the KX500 Clutch arm and removed the arm from the shaft.

Image

After carefully measuring the parts, I took it to a friend of mine who is a machinist and had him part both the shafts.
Once I verify the measurements I'll have it welded.

Image
More later
If bikes are for kids I'll never grow up.

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Sandblaster
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Re: How to make a KX500 billet extended clutch arm.

Post by Sandblaster » Thu Aug 09, 2012 8:39 pm

After I verified the correct placement in the bike I chamfered one of the shafts to provide a good welding surface:

Image

Not shown on the picture is I chamfered the slot to allow for weld.
Here is the measurements I settled on:
Image

The shafts have been welded and the slot has been filled with SS.
The shafts were clamped down in a V-block to maintain alignment while welding:

Image

We'll spin it up tomorrow on the lathe and see where it cleans up at.
If bikes are for kids I'll never grow up.

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Sandblaster
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Re: How to make a KX500 billet extended clutch arm.

Post by Sandblaster » Fri Aug 10, 2012 6:14 pm

All done :D

Image

It will be some time before I can mount it up and try it but I'll let you know what I think when I get it done.
Feel free to post comments and ask questions.
Thanks!
SB
If bikes are for kids I'll never grow up.

Motorrad
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Re: How to make a KX500 billet extended clutch arm.

Post by Motorrad » Tue Feb 12, 2013 12:43 am

Damn.. awesome Idea... wish I thought of it... :lol:


Image
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Re: How to make a KX500 billet extended clutch arm.

Post by Sandblaster » Tue Feb 12, 2013 1:31 am

You did.
I steal all your good idea's :o
By the way, you can sure make a nice weld.
If bikes are for kids I'll never grow up.

Motorrad
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Re: How to make a KX500 billet extended clutch arm.

Post by Motorrad » Tue Feb 12, 2013 2:18 am

Sandblaster wrote:You did.
I steal all your good idea's :o
By the way, you can sure make a nice weld.

and I thought it looked like crapola...
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Re: How to make a KX500 billet extended clutch arm.

Post by Sandblaster » Tue Feb 12, 2013 2:35 am

That's because you haven't seen what my welding looks like :-)
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Re: How to make a KX500 billet extended clutch arm.

Post by Sandblaster » Mon Jan 27, 2014 11:18 pm

Here is some basic measurements
KX500 EXTENDED CLUTCH ARM.JPG
KX500 EXTENDED CLUTCH ARM.JPG (42.6 KiB) Viewed 11519 times
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