From cold when starting it immediately comes to life then over the next 2-3 seconds stops. Choke doesn't help. After another 2 or 3 goes and by then it will accept a little throttle to help thing along and all then is ok. At this point I use the choke for about 20 seconds to keep the idle at about 1300.I have owned the bike for 1 month and have hardly ridden it as not allowed to for 4 more weeks.It had sat in a garage unridden for 1 year prior.Bike has slip on, aftermarket jet needle and jets prof installed. I suspect adjusted TPS as tacho at 10K. When warm engine runs well no flatspots and produces great power.I have drained all of the old fuel out by removing the tank and letting the engine starve to cut off. Then new plugs and fuel, same problem but not quiet as bad.Carby removal and clean?Just exploring options, any advice would be appreciated.