Backfire when starting

causes of backfire
ignition timing
bad reeds
jrtting way off (usually rich)
blue bike color ( red will make it start soooooo easy:) )

if your reeds are wet it sure sounds like you're getting too much fuel. could your pilot be off, or your air screw?
a weak ignition can also cause the same problem.
one last question. sorry it this is too basic of a question, but are you applying any throttle when kicking? The normal starting drill is choke no throttle.
oh yes, the float may be sticking, or the float needle seat, or the matching viton tip could be bad. I had a friend who had a bad float that caused the carb to massevlt flood. the bike was a beast to start. once it was running the bike ran like a champ.
hope any of this helps, especially the suggestion about the red bikes:) :)

I've checked the ignition and the stator seems to be fine. The only thing that was slightly out of spec was the ignition coil. It was supposed to have a resistance of 0.2 to 0.3 and I had 0.4.

that's probably the answer

sounds like you've eliminated all the other possible culprits.

if you want to check the fuel shutoff you'll need to remove the bottom of the carb (or the whole thing if necessary). hool up the fuel line and turn the fuel valve on (the editor will not let you say pet****). lift the floats until they are parallel with the side of the carb ( the edge where the bottom meets the top). the fuel flow should stop. it may go a little past parallel, but too much and the bike is proably flooding.
If your stator readings were out of the specs, you probavly have a bad coil which would definately cause the problem.
good luck
the blue ones aren't that bad, at least it's not yellow or green.:)

Heres a solution that might be your problem. I had a similar problem at work the other day on a learjet. Customer complained of intermittent thrust reversers. Turns out it was a squat switch that had bad resistance readings and when it got cold, resistance changed drastically. Electrical components dont like the elements and start to go crazy. Take your coil and let it get warm. You could put it in front of your car heater vent for about ten minutes or so. Check the resistance. Take it and put it in the freezer and let it cold soak for 20-30 minutes or spray it with a can of freeze it while watching the meter. That coil may be on the verge of taking a crap. Once it gets some heat in it, then it may work. I know this may sound like bs, but trust me. Another possibility is timing. If you checked it visually check it again by pulling off the flywheel and inspecting the Woodruff key on the crank. It may have broken or started to shear. You should really suspect this if you or someone else has had the flywheel off in the past. hope this helps