I plan to do a full rebuild on my zx10rr at about 4000km, the Thai Kawasaki Sbk team changes valves every 2000km.
If you keep the engine completely stock then they seem to last pretty good but once you add a little extra (race cams) then they donít hold up so well. My teammates just had to have their BSB spec engines completely rebuilt, one lasted just over 4000km and the other bent a valve just under 4000km.
Sent from my iPhone using Tapatalk
Wow, so shimming the valves isn't enough, actually need to replace the valves completely?