[alex.s]

Originally Posted by spooph

The reason each cylinder is different is because Kawi designed cylinder 1 to be the "torque" side, and cylinder 2 to be the "power" cylinder.

The 250 is down on power, we all know this. To keep things cheap it was easier to split the power load between the two cylinders to make a more rideable bike, providing more power down low compared to the pre-gen 250's.

I'm sure you noticed the headers are different lengths between the two cylinders. When adding on an aftermarket header, which has equal length headers it's best to replace the needle and idle mixture screw on cylinder 1 with a set/part number intended for cylinder 2.

Example:
So, cylinder 1 is the torque cylinder, with a longer header tuned for more torque.

Cylinder 2 is the power cylinder, with a shorter header tuned for more top-end power.

If top end power is what you're after, with an aftermarket exhaust system with equal length headers, you should match the internals of cylinder 1's carb with those of cylinder 2. IF you're tuning for torque down low to make get the bike more pickup below 4K RPM's, you'll have to weld up your own header, equalizing pressure and tuning for more torque and match the internal of cylinder 1's carb.

Now this is all applying to the inifinite degree. What most people do with aftermarket headers is to go to the dynojet needles and to not worry about the idle mixture screw in cylinder 1's carb and fudge it close enough, however, you seem to be going to the infinite degree, so I would recommend to also match the idle mixture screws to those found in Cylinder 2's carb.

I hope all of that makes sense.

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