I had the same problem. I tested the CR's and they seem to be working. Still did it. I rewired the CR's to the starter direct. Still did it. I replaced the CR's. Still did it. So in my opinion, if you test them and they are moving then that is not the problem. I ended up living with it. Later I had a oil pump issue and deciced to do a engine rebuild. I removed the engine from the bike. which included the primary system, clutch and starter. engine was rebuilt. I put it back together. I got alittle over 1000 miles on bike. It has not clunked at all. Now I'm not saying you have to rebuild your motor. You may want to check your primary chain. I installed a auto chain adjuster. I would also would remove the compensator, clean it, inspect it, reinstall. Do the same to the clutch. and make sure you retorque both components. Another thing that could cause the clunking startes is if your ignition timing is too far advanced. Everything i suggested that you do is what i did putting the motor back into the bike. so I can't narrow down what caused it. but I'm not experiencing htat problem anymore. hope this helps.