What does your sled have for clutching and gearing? Stock clutching should be gold primary spring with 10-54 weights and 18/41 gears. You could try a dark blue/white primary spring with a set of 10-56 weights, maybe 10-58??
Jet the mains to 390, needle middle clip. Change the primary spring to an erlandson white, and the weights to 10-56. Change the helix to a hot seat HSP34X, #2 hole with the stock silver/blue. Be sure to run BR9ES or RN2C plugs, and a 3211074 belt. Have the clutch alignment checked, and the engine torque stop set tight, no gap. For riding at low elevation (1500-2500ft) I would also gear it up some, to 19/39, 19/40. Stock it is only geared for 75 mph.
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