Valve troubles

[Gerard kenn]

I've just put an oversize 150 cam and new valves in my lifan125 and it's running fine but it has a knock in the head the timing is fine and the valve clearances are good I have no idea whats going on can anyone help doing my head in

 

[sm00th]

Check the valve springs. With the bigger cam you may have coil bind

 

[needapitty]

what cam is it and what valve springs did you use mate

 

[zwebx]

i agree, it would probably cause the valves to bounce if the valve springs are too weak..

 

[DHZ_XR8cing]

Check your valve to piston clearance