I have had a problem with what seems like a "flat" spot in the throttle. my bike seems to lose power at a certain spot, less that or about 1/4 throttle. This only happens at higher altitudes. I live @ 5000' but ride in the hills 8,000'- 10,000'. I have tried adjusting the fuel screw to no avail. I have checked the jetting data base but have not found exactly what I'm looking for, here are my jet numbers. main 155 pilot 42 starter 72 needle 3rd notch down Any feed back will be very appreciated. Thank you.