Tom, when you say "seems" to be too lean, doesn't sound like you did a plug check. Take the time to pop off the front and side plastic. Do a 1/4 throttle run, stabilizing the throttle for at least 1/4 mile then use the kill swithch on the bars to kill the ignition. Coast to a stop. Shut the gas off. Slip a golf-tee in the fuel line going to the pump (helps eliminate fuel spilling back). Loosen the tank and slide it out of your way. Do this for the 1/2, 3/4, and wide open throttle also. Get yourself some di-electric grease from your local auto store also, and put a dab of that inside the sparkplug boot. Also are you familiar with where the pilot adj screw is on this carb? You have to drill out a factory plug. It's the forward most brass plug on the bottom of the carb, in front of the float-bowl.