I have the copperhead VDI and Dynojet kit installed. The jet kit recommended 2 turns out for a Air/fuel mix.

Elevation is about 2000 feet and temperature today was about 60F. I am jetted with the recommended 144/150 jetting.

The quad really didn't stumble or stall, but I could smell un brunt gas all day. I tore it down again and went with 1.25 turns out on the front and rear air/fuel screw. I won't have a chance to test it till this coming weekend so I am hoping this is better.

Anyone else with similar experience?

 

Curls, I had almost the same experience. I too have the VDI and DynoJet if I punched it from a stop I would get hesitation (sometimes a full engine stall)and a puff of black smoke at the start when at the Dynojet recommended setting. I then started to adjust and I found that as I turned the screw in the hesitation was less and less every 1/4 turn in on the mixture screw. I ended up with the screw 1 turn out from the bottom with no hesitaion, smoke puffs, or backfiring on deceleration. The copperhead runs great on a very lean idle mixture. The VDI manual actually says this with some instructions on adjustment procedures.