KX500 CYLINDER CUT AWAY!

Dirt Bike Technical discussion. This is for a little more in depth discussions :-)
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Sandblaster
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KX500 CYLINDER CUT AWAY!

Post by Sandblaster » Wed Jun 19, 2013 11:50 pm

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 :D
KX500 CYLINDER CUT AWAY 1.PNG
KX500 CYLINDER CUT AWAY 1.PNG (682.17 KiB) Viewed 4276 times
KX500 CYLINDER CUT AWAY 2.PNG
KX500 CYLINDER CUT AWAY 2.PNG (605.61 KiB) Viewed 4276 times
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Sandblaster
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Reed Valve Fitment V-Force 3

Post by Sandblaster » Thu Jun 20, 2013 8:03 pm

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
V FORCE 3 KX500 1.PNG (643.48 KiB) Viewed 4229 times
V FORCE 3 KX500 2.PNG
V FORCE 3 KX500 2.PNG (552.67 KiB) Viewed 4229 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
V FORCE 3 KX500 3.PNG (984.56 KiB) Viewed 4229 times
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KX500 Reed Valve Fitment V-Force 3

Post by Sandblaster » Thu Jun 20, 2013 8:04 pm

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
V FORCE 3 KX500 4.PNG (895.96 KiB) Viewed 4229 times
By the time you install the reed all the way in look how far it is pinching shut :o
V FORCE 3 KX500 5.PNG
V FORCE 3 KX500 5.PNG (1.13 MiB) Viewed 4229 times
Here is the side view of the same thing.
V FORCE 3 KX500 6.PNG
V FORCE 3 KX500 6.PNG (1.12 MiB) Viewed 4229 times
V FORCE 3 KX500 7.PNG
V FORCE 3 KX500 7.PNG (770.6 KiB) Viewed 4229 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 :shock:
Even if it did open up that much you would probably loose velocity.....
V FORCE 3 KX500 8.PNG
V FORCE 3 KX500 8.PNG (828.91 KiB) Viewed 4228 times
As you can see, this is not really the best of designs..
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KX500 Reed Valve Fitment V-Force 3 WITH REED SPACER

Post by Sandblaster » Thu Jun 20, 2013 8:05 pm

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
V FORCE 3 WITH 10MM SPACER KX500 1.PNG (815.83 KiB) Viewed 4229 times
Here is a side view of the same thing.
V FORCE 3 WITH 10MM SPACER KX500 2.PNG
V FORCE 3 WITH 10MM SPACER KX500 2.PNG (536.73 KiB) Viewed 4229 times
Here is a view with the reed all the way in.
V FORCE 3 WITH 10MM SPACER KX500 3.PNG
V FORCE 3 WITH 10MM SPACER KX500 3.PNG (536.67 KiB) Viewed 4229 times
As you can see it is better but still far from optimal...
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STOCK KX500 REED VALVE FITMENT AND CUTAWAY

Post by Sandblaster » Thu Jun 20, 2013 11:11 pm

This is the stock reed..
It does not have any interference fitment issues..
KX500 STOCK REED CUT AWAY 1.PNG
KX500 STOCK REED CUT AWAY 1.PNG (1.21 MiB) Viewed 4217 times
KX500 STOCK REED CUT AWAY 2.PNG
KX500 STOCK REED CUT AWAY 2.PNG (1.25 MiB) Viewed 4217 times
KX500 STOCK REED CUT AWAY 3.PNG
KX500 STOCK REED CUT AWAY 3.PNG (1 MiB) Viewed 4217 times
KX500 STOCK REED CUT AWAY 4.PNG
KX500 STOCK REED CUT AWAY 4.PNG (1.04 MiB) Viewed 4217 times
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STOCK KX500 REED VALVE WITH A 10MM SPACER

Post by Sandblaster » Thu Jun 20, 2013 11:12 pm

This is the stock reed with a 10mm spacer..
KX500 STOCK REED AND 10MM SPACER CUT AWAY 1.PNG
KX500 STOCK REED AND 10MM SPACER CUT AWAY 1.PNG (984.54 KiB) Viewed 4217 times
KX500 STOCK REED AND 10MM SPACER CUT AWAY 2.PNG
KX500 STOCK REED AND 10MM SPACER CUT AWAY 2.PNG (916.69 KiB) Viewed 4217 times
KX500 STOCK REED AND 10MM SPACER CUT AWAY 3.PNG
KX500 STOCK REED AND 10MM SPACER CUT AWAY 3.PNG (1.17 MiB) Viewed 4217 times
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KX500 V FORCE 2 CUT AWAY

Post by Sandblaster » Thu Jun 20, 2013 11:59 pm

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 :D
KX500 V FORCE 2 REED VALVE 1.PNG
KX500 V FORCE 2 REED VALVE 1.PNG (630.85 KiB) Viewed 4214 times
KX500 V FORCE 2 REED VALVE 2.PNG
KX500 V FORCE 2 REED VALVE 2.PNG (847.63 KiB) Viewed 4214 times
KX500 V FORCE 2 REED VALVE 3.PNG
KX500 V FORCE 2 REED VALVE 3.PNG (1.14 MiB) Viewed 4214 times
KX500 V FORCE 2 REED VALVE 4.PNG
KX500 V FORCE 2 REED VALVE 4.PNG (1.85 MiB) Viewed 4214 times
Thanks goes again to Tobys Two Strokes and Motorrad for their help with this project...
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KX500 V FORCE 2 CUT AWAY with 10mm spacer

Post by Sandblaster » Fri Jun 21, 2013 12:13 am

Same thing but with a spacer...
KX500 V FORCE 2 REED VALVE WITH 10MM SPACER 1.PNG
KX500 V FORCE 2 REED VALVE WITH 10MM SPACER 1.PNG (1.23 MiB) Viewed 4212 times
KX500 V FORCE 2 REED VALVE WITH 10MM SPACER 2.PNG
KX500 V FORCE 2 REED VALVE WITH 10MM SPACER 2.PNG (1.13 MiB) Viewed 4212 times
KX500 V FORCE 2 REED VALVE WITH 10MM SPACER 3.PNG
KX500 V FORCE 2 REED VALVE WITH 10MM SPACER 3.PNG (1.35 MiB) Viewed 4212 times
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Re: KX500 CYLINDER CUT AWAY!

Post by Sandblaster » Sun Jun 23, 2013 3:49 pm

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

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Sandblaster
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Re: KX500 CYLINDER CUT AWAY!

Post by Sandblaster » Wed Jul 17, 2013 8:29 pm

It's time to look at some of the ports...
PORTING.JPG
PORTING.JPG (22.28 KiB) Viewed 4016 times
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