I assume you're meaning slide cut, 5/6/7 etc. It has most effect at 1/4 to 3/8 throttle. The higher the number the leaner the slide. It helps the transition from pilot to needle and shapes the power a bit.
Once you have a good pilot jet, strong idle and a needle that performs well, the stock slide is fine. If you like the needle taper everywhere but it's a bit iffy off idle, changing the slide can clean things up. Keep in mind that any slide change might require a needle change.
__________________
2011 EC250E
|