Hi, I hope I'm not hi jacking this thread too much, I just bought a 2001 DRZ400E, after a 15 year hiatus from dirt bikes. This is my first four stroke since probably 1976. I was a two stroke guy for most of my riding life. So this DRZ has a FCR39 carb . . . more tubes than any Mikuni I ever worked on. . . . . The bike has good power, but I notice some things that I would like to troubleshoot. 1. There are certain times, not every time, when I chop the throttle, the bike backfires. When it does this, if I pull the clutch in, she'll stall . . . . my guess is a lean condition?? Is that what the coast enrichener is supposed to prevent? Is the coast enrichener a mechanical thing that can get gummed up by sitting around with old gas? Finally, what is removing this and putting a fatter low speed jet in a cure for? ( I have read that this is a good mod) 2. When she starts the engine speed is not what I would expect. She starts and turns at a lower rpm, then increases to a fast idle. . . . is this by design or is it a clue? Anyways, I have other questions, not carbie related, so I'll hijack another thread for that. Thanks .