Hello, I am trying to Sell my 01 YZ426F, so I tried getting it started today which is where I ran into a problem. The bike would only start with the choke on and would not idle at all... I had to have the throttle open for it to run. I tried cleaning the air filter, I replaced the spark plug, and put brand new premium gas in it. Still it was doing the same thing. When it was running it was sputtering and backfiring like crazy! Anybody have any sugestions for me?!?!