I had problem with hard starting (especially when warm) for awhile, but it ended up being a tuning problem. The engine would fire easy enough, but would surge and quit, no matter the throttle setting. I was sure it was a fueling problem, but I couldn't find anything wrong. I'd previously had the engine running well and thought the needles were fine. I eventually tweaked the settings a bit and find out that my low needle was off by about a full revolution. Anyway, since that adfjustment my engine has been good.