Last week I bought a 1982 Yamaha XJ650 with 11,000 miles on it. No mods in good condition. Starts well, tick over fine but from 1,300 rpm to 3,000 rpm it hesitates, feels rough with very uneven power delivery. But from 3,000 rpm or so it is perfect, pulling cleanly and smoothly. Any ideas where I should start? As an older rider I like to spend a good part of my trips pottering along at up to 3,000 rpm, I'd like to do it smoother than now. Any suggestions welcome. I also posted this in the vintage section earlier.

Try balancing the carbs Simon

I'm having some similar issues with my XJ650J. I have a thread here about it. I've been building a tool to help with synching the carbs. Once I do it all I'll film it and put it up on YT.

Hi Simon_did you ever resolve that low rev missing as I have the exact same issue?

Pete in South Africa