I have a 2003 kfx 400. Original owner. Pipe and jetted. Bike ran fine last year. Upon trying it this year it seems to want to bogg and stall out when i gear down , and go slow at low idle over bumpy terrain. Why is this hapening? It starts and idles like new. Only when the bike is bounced around that it wants to stall. Changed out fuel As well but got no results.
Help would be great thanks.