KX500 CYLINDER CUT AWAY!

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KX500 CYLINDER CUT AWAY!
Thanks to Tobys 2 strokes for donating a KX500 Cylinder.
Have you always wondered how it all works or what happens when in relation to....
We will explore this together

KX500 CYLINDER CUT AWAY 1.PNG (682.17 KiB) Viewed 18276 times

KX500 CYLINDER CUT AWAY 2.PNG (605.61 KiB) Viewed 18276 times

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So, how do the reed valves fit into the cylinder?
I'll start with a V-Force 3 and go from there...

V FORCE 3 KX500 1.PNG (643.48 KiB) Viewed 18229 times

V FORCE 3 KX500 2.PNG (552.67 KiB) Viewed 18229 times

This is how far the V Force 3 will slip into the cylinder before the reed begins to touch on the top and bottom.

V FORCE 3 KX500 3.PNG (984.56 KiB) Viewed 18229 times

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Here is a view from the side to show just how much further the reed valve has to go into the cylinder and it is already touching on the top and bottom.

V FORCE 3 KX500 4.PNG (895.96 KiB) Viewed 18229 times

By the time you install the reed all the way in look how far it is pinching shut

V FORCE 3 KX500 5.PNG (1.13 MiB) Viewed 18229 times

Here is the side view of the same thing.

V FORCE 3 KX500 6.PNG (1.12 MiB) Viewed 18229 times

V FORCE 3 KX500 7.PNG (770.6 KiB) Viewed 18229 times

This view shows how much material would have to be removed in order for the reed to be able to fully open.
While the cylinder could be opened up enough on top to make that happen, the bottom is too thin.
It's hard to see from the picture but the 3 "X"'s are part of the excess casting.
If I removed it you would see that the bottom would be extremely thin, and I suspect it would probably break all the way through
Even if it did open up that much you would probably loose velocity.....

V FORCE 3 KX500 8.PNG (828.91 KiB) Viewed 18228 times

As you can see, this is not really the best of designs..

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Here is a view with a 10mm reed spacer installed.
This is how far it will slide into the cylinder before the top and bottom start to touch.

V FORCE 3 WITH 10MM SPACER KX500 1.PNG (815.83 KiB) Viewed 18229 times

Here is a side view of the same thing.

V FORCE 3 WITH 10MM SPACER KX500 2.PNG (536.73 KiB) Viewed 18229 times

Here is a view with the reed all the way in.

V FORCE 3 WITH 10MM SPACER KX500 3.PNG (536.67 KiB) Viewed 18229 times

As you can see it is better but still far from optimal...

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This is the stock reed..
It does not have any interference fitment issues..

KX500 STOCK REED CUT AWAY 1.PNG (1.21 MiB) Viewed 18217 times

KX500 STOCK REED CUT AWAY 2.PNG (1.25 MiB) Viewed 18217 times

KX500 STOCK REED CUT AWAY 3.PNG (1 MiB) Viewed 18217 times

KX500 STOCK REED CUT AWAY 4.PNG (1.04 MiB) Viewed 18217 times

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This is the stock reed with a 10mm spacer..

KX500 STOCK REED AND 10MM SPACER CUT AWAY 1.PNG (984.54 KiB) Viewed 18217 times

KX500 STOCK REED AND 10MM SPACER CUT AWAY 2.PNG (916.69 KiB) Viewed 18217 times

KX500 STOCK REED AND 10MM SPACER CUT AWAY 3.PNG (1.17 MiB) Viewed 18217 times

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Here is the same basic pics with a V Force 2.
I think it is becoming self evident why I will be running a V Force 2 in all my machines

KX500 V FORCE 2 REED VALVE 1.PNG (630.85 KiB) Viewed 18214 times

KX500 V FORCE 2 REED VALVE 2.PNG (847.63 KiB) Viewed 18214 times

KX500 V FORCE 2 REED VALVE 3.PNG (1.14 MiB) Viewed 18214 times

KX500 V FORCE 2 REED VALVE 4.PNG (1.85 MiB) Viewed 18214 times

Thanks goes again to Tobys Two Strokes and Motorrad for their help with this project...

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Same thing but with a spacer...

KX500 V FORCE 2 REED VALVE WITH 10MM SPACER 1.PNG (1.23 MiB) Viewed 18212 times

KX500 V FORCE 2 REED VALVE WITH 10MM SPACER 2.PNG (1.13 MiB) Viewed 18212 times

KX500 V FORCE 2 REED VALVE WITH 10MM SPACER 3.PNG (1.35 MiB) Viewed 18212 times

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There has been some controversy over the years about using a V-Force 2 over using the V-Force 3.
However, all the dyno results I have seen have consistently shown the V-Force 2 to be superior in the big KX500.
That is not to say the the V-Force 2's are without problems.
The reed pedal bolts have been known to loosen.
Ingesting a metal bolt with your engine, no matter how small, is never a good thing, so use loctite on all the bolts..
All that being said, I will use a V-Force 2 in all my K5's.

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It's time to look at some of the ports...

PORTING.JPG (22.28 KiB) Viewed 18016 times