Jackpiner jetting

[Tommy_V]

Hey Guys,

I rebuilt my Bing on my 74 Jackpiner.  New slide, floats, float needle and seat, main (145), pilot (30), needle jet and jet needle.  Rode her a little tonight, 45 degrees, sea level.  With the new slide there is no idle adjustment due to the notch in the new slides.  To get it to idle down I had to turn the air screw all the way in.  That means too lean, need a bigger pilot, right?  Anybody have and bing 30 mm jetting specs they want to share?

Thanks,

Tommy

[hrbay]

Tommy, how is it starting? First kick after tickling? You want to make sure that you can hear a clik as you open and close the throttle. You want to hear both extremes of the slide moving up and down. If you don't it may not be closing completely making your tuning more difficult. Did you leave the idle screw in place, just backed out some? If all is fine a larger pilot will allow you to adjust the idle on the cable, which is what you want. Turning the air screw all in shuts off the air bleeding into your idle circuit. The pilot is a 30... so you will want a richer pilot that will give more air adjustment, (allow you 3 - 1/2 turns out on the air screw), a 40 will probably get it close.

GC

[Tommy_V]

I figured it out, I had an air leak on the intake side of the carb.  I put an o-ring in the mouth of the carb and reinstalled, problem solved.



Tommy

[tlanders]

Tommy,

I put on a 32MM Bing on my piner and it works great. It has a 150 main, 2.74 needle jet and I think a 30 pilot. The bike is reallly fast and I love it. Are you riding your Piner at the VISDT this weekend?

Teddy