verslagen1 wrote on 09/09/08 at 22:06:45:Pilot jet is for up to 1/8 throttle or thereabouts. I'd don't know how you ride but I give 1/2 throttle more or less up thru the gears and hold it there till I have to stop. So pilot has the least effect on my gas mileage.
Taking off, you're sucking gas,.. but while cruising, the engine is at high vacuum, pulling the slide needle down into the jet passage,...so most of the gas is coming from the pilot circuit. Spacing the needle increases that some, but the engine requires little gas to cruise at a steady 60mph.
70+ for me, seems to start opening up the needle and then you're right,... it's on to the needle/main curcuit.
Here's a quote from Mikuni,
"Normal highway cruising speeds (65 mph/ 100 kph) require rather low throttle openings, generally less than º throttle. Air/fuel ratios in this throttle range are controlled by the pilot circuit together with the jet needle and needle jet. Thus, poor fuel economy at normal cruising speeds should be addressed by altering or adjusting these parts."