jaguar
~SPONSOR~
I'm sure this is a common occurrence, that someone puts in the richest main jet for clean running and yet the piston still shows signs of lean jetting (too little wash and burnt oil under the piston crown).
1. You ride whiskey throttle. Complete opening of the throttle too early means there will be less vacuum on the needle jet to pull gas up into the venturi which will make the mix lean. The vacuum there depends on RPM and throttle position. More area under the slide means a great dispersion of the vacuum, leaving less at the needle jet.
2. Your throttle opening is proportional to the RPM but the mid throttle jetting is lean. This can be corrected with a needle with more taper angle. See my needles pages which lists the angles: www.dragonfly75.com/moto/needles.html
1. You ride whiskey throttle. Complete opening of the throttle too early means there will be less vacuum on the needle jet to pull gas up into the venturi which will make the mix lean. The vacuum there depends on RPM and throttle position. More area under the slide means a great dispersion of the vacuum, leaving less at the needle jet.
2. Your throttle opening is proportional to the RPM but the mid throttle jetting is lean. This can be corrected with a needle with more taper angle. See my needles pages which lists the angles: www.dragonfly75.com/moto/needles.html
