Motorcycle Repair: CL350K2 top end noise, camshaft lobes, cam bearings

Question
Hi Bill,
The con rod upper end is scored near the oil hole at top of rod.
the wrist pin has no play and the motor was not making a heavy knocking noise. I don't know if it was run low on oil before I got it at 6k but I have put 4k on it last year. I get 160psi both cyl.
Paul VJMC#10902

Answer
If there are any rough edges on the scoring, you can smooth them down slightly. Oil up a new wrist pin before you install them again. If no excessive play, then that should be okay. Pull the rods up and down to see if there is any vertical play/motion in the big ends. There should be none.

During assembly, be sure that the head gasket is indexing properly on the knock pins and is evenly concentric with the cylinder bore edges. Some aftermarket gaskets were punched off-center, so the edges of the fire ring on the gasket will contact the edge of the piston at TDC.

160psi is about right, considering you are trying to draw through closed CV carburetor slides. As you reassemble the top end, turn the engine over by hand after you have set the cam timing and tensioner adjustment and listen for any unusual noises or feel any kind of contact happening during rotation. Factory specs are 175+- a few psi.

Be sure to change out both side cover gaskets.. dyno and clutch, if they haven't been changed already. The originals will deteriorate, with pieces that break loose and float up into oil passages blocking lubrication to the top end. This is from a Honda TSB, covering most of the original 350 engine line-up. That will create knocking, plus seizures of the cam bearings and galling of the camshaft lobes and rocker arms.

Bill Silver