I have a 2003 TE610E, which is the same bike. My bike has a slight surge at around 30mph, which I was told was ECU related, but runs fine at 3500 rpm. I can't find my jetting notes right now, but basically you need to upgrade to the same jetting specs, as a 2000 TE610 left kick enduro bike. On the Dellorto, the AB nozzle is important. At every gear the bike misses only at 3500 rpms.
