[SpudRider]

Valve recession occurs when the face of the valve recedes into the valve seat in the cylinder head. If not corrected, the valve face and valve seat will continue to erode until the valve leaks, and damages the cylinder head.

Valve recession can be caused by several factors. If you don't regularly oil and clean your air filter, dirt can enter the engine and cause valve recession. A leak in the intake manifold can also allow dirt to enter the cylinder. Defects in either the valve face or the valve seat can also cause valve recession. Since I have always properly maintained my air filter and I did not find an leaks in the intake manifold, I must assume the valve recession in my engine was caused by a manufacturing defect. Hopefully the new cylinder head and new valves have corrected this problem. As always, I appreciate the excellent warranty coverage I received from CSC Motorcycles in Azusa, CA.

The exhaust valves in my engine finally did stablize after about 16,000 miles. I did notice damage on the exhaust lobe of the camshaft. I replaced the camshaft during the engine rebuild.



Both of the roller rockers were in good condition, so I did not replace them.