After the restoration: Cam Woes [page 3]
Wednesday, Jan 8 2014 [25,724 miles]
right cylinder and piston
I pulled the cylinder and piston from the right side of the bike. I measured the right cylinder and found that unlike the left it was slightly out of round. There was a .01mm difference between vertical and horizontal measurements at the top of the cylinder. There is also a 0.03mm difference between the ends of the cylinder and the middle.
Also, the fingernail test can feel some of the score marks that I can see on the left cylinder. I’ll be ordering 3rd oversize pistons and getting the cylinders bored to 73.5 mm.
tappets and cam
I pulled the tappets from both sides to take a look. The pictures tell the story. Both exhaust tappets are pitted. Both intake tappets are just starting to pit. Worse, the cam will have to be replaced. Again. The picture doesn’t show the damage very well but you can feel the wear with your finger. Large craters worth of wear. The cam will come out next.
Thursday, Jan 16 2014 [25,724 miles]
I’ve finished the GS 6K service so can now get back to the R69S. I’m going to pull the cam withough removing the engine from the bike. I started by draining the oil. This was not strictly necessary, but I wanted to see if there were any metal bits on the magnetic plug or in the oil. Didn’t notice any. I also disconnected the battery.
remove generator and magneto
I pulled the front cover, the advance mechanism, and the R69S damping mass, first. Then, after disconnecting all wires I removed the magneto and generator bodies. I pulled the generator armature and placed it in the generator body for storage. I pulled the magneto rotor last, placing it in the magneto body.
remove timing case cover
I used my Ed Korn all-in-one tool to pull the timing case cover.
Pulling the cam
An air impact made loosening the cam retaining screws an easy job. Well, mostly easy. One of the four screws wasn’t in the best shape. It will be replaced. I don’t know if I damaged the slot in attempting to remove the cam now or if it was damaged when I installed the cam in ‘10.
Ouch! Not only were the exhaust cam lobes shot, but a very small chunk of the cam was missing. Apparently that chunk wound up between cam and crank timing gear, causing much damage.
I’m taking parts and a parts list over to Brent’s next Tuesday to start the repair process.