800 exhaust valve actuator cycling

[JMCX]

I helped a friend do a top end on their motor. For the first few hours everything was fine. Then it wouldn't spin over 7000 rpm. What they found is that the exhaust valve actuator starts rapidly opening and closing at 7000 rpm. Anyone know what would cause this? There are no codes coming up?

 

[JMCX]

I'll answer my own question. The cable was broken. I can only guess that the actuator was cycling because the rpm was surging. Putting it above and below the rpm actuation point.

 

[banditpowdercoat]

Yup, thats what happens when the cable breaks. No codes either with mine.