I have a 2006 1200C with 8000 miles and from what I can find out one of the tappet rollers has a flat spot. Had a metalic clunking noise develope at idle, rode it like I stole it back home 200 miles and it has'nt got much worse.Just wondered if anyone has had this happen and if you had to replace the cams also.Thanks

 

In general the stock tappets are very reliable, and fairly often can last the life of the bike. Is your bike setup pretty close to stock? If you have done any modifications like heavier valve springs with high lift cams, that definately will put a lot more stress on the tappets. So did you actually see the tappet yet, or are you just assuming it has a flat spot??? As for the cams, you just gotta pull out the cam and check it out to see if it's damaged or not. But if you are just assuming its the tappet, and you haven't actually seen it yet, then you just gotta dig in there and check things out. There's just too many things that will give you metallic clunking sounds for you just to assume what the problem is.

 

Have you run a compression test yet? Less than 15 minutes to do both cylinders, it is worth it. You can rent/borrow the tools at any of the larger chain auto parts stores.

 

I had an Andrews rear exhaust cam go round, with just a little blade of the profile on one edge. Made quite a racket. Power delivery fell off significantly.
Could also be a collapsed lifter.