I'm assuming you have good compression (good resistance when using the pull start). It sounds like the engine may be flooding with too much fuel. Putting fuel in the cylinder first will make the problem worst. Another problem is that unless you can raise the rear wheel like with a center stand, it will be hard to use the WOT start to clear the engine. I have had problems with sediment or dirt in the carb which caused flooding. To check for a flooding problem, you might try keeping the fuel valve shut off and try starting with the throttle wide open (no choke). This may take a few tries because there is still some gas in the carb which has to clear out. Sometimes using starting fluid sprayed in the air filter will help when doing this because it ignites more easily and will help clear raw fuel out. If this works, make sure you have a good fuel filter installed to prevent it from happening again. Good luck.