Originally Posted by Itchi
*Procycles jetting kit (dyno tuned at 39hp)
I don't recommend the DynoJet needle that comes in the PC kit because:
1) It's a shape that is likely to produce significant variances in mixture strength throughout the rpm range (richer toward the bottom relative to the top).
2) It's made out of stainless steel which means more emulsion tube wear than with an aluminum needle.
3) It doesn't use the white plastic spacer under the clip, which means the needle is not preloaded in the downstream direction, and will therefore be more prone to orbiting/otherwise gyrating inside the emulsion tube. It also means that the needle will not be able to pivot out of the way as the slide guide wears. Both of these factors equate more emulsion tube wear.
Has the slide been drilled?
*High flow K&N filter and high flow oil filter.
As others have noted, the K&N is not likely to filter adequately off road. The standard under-diaphragm vent filter is also inadequate and will contribute to accelerated slide guide, silde, emulsion tube and jet needle wear when the bike is ridden in dusty conditions. I recommend replacing the standard under-diaphragm vent filter with an oiled Uni UP-123.