angusec

mine is still under warranty, so I had the service done by the dealer.

Now, that said, I have adjusted lots of valves on cars. I have never had to change a valve to obtain proper clearances. I suspect the measurements might be off, or the math? No disrespect, it happens to everyone I know its a pain to check it again, but I'd do that. If its done well, and its still too tight, maybe post up on the engine part? Or over at the Duke390 forum?

Hi, I’m having the same issue as you described with your RC390. I was running a bit tight on the left exhaust valve so I changed the shim for a thinner one but the clearance lowered. The new shim doesn’t have a taper on the edge but the old does. Did you have to change the valves? Did it help? I’ll be glad if you could tell me how you resolved the issue.