I'm a new rider (only a few months) and I bought a 2001 Ninja 250 to learn on. I rode it for a month before this started to happen. The bike will only start with the choke on. When you roll the choke off, it dies. When you roll the throttle, it dies. It idles fine, around 1800 rpm with the choke. But as soon as you touch the throttle it sputters and dies. Every time.Changed the spark plugs, oil, airfilter, and adjusted the throttle cables. Ran Seafoam through and drained the gas tank and put new gas in. I haven't taken the carbs off yet to clean/ inspect but that is the next step unless you guys can help me out! Any suggestions are appreciated!