Clicking in motor 1978 yamaha xs650?

Question

I have a yamaha xs650. When i ride for a while or when the engine warms up, a clicking starts to come from the motor. it does not get proggressivly louder, but is cause a concern for me. anyone know what that is causing??????

Answer 1

Nomadd has his bikes confused. The 78 XS650 is the overhead cam twin cylinder model with screw adjusted valves not shims. He is correct however in suggesting valve adjustment and cam chain adjustment. Personally, I would start with cam chain adjustment as it is very easy on that bike. Simply remove the cover of the adjustor, rotate the engine while observing the small shaft that exists in the hole in the middle of the adjuster. Loosen the locknut on the body of the adjuster and screw the body in or out (no doubt will need screwing in) till the end of the shaft is flush with the end of the adjuster body, put the cover back on your done.

Answer 2

It's kind of hard to guess a noise, but the valves are a likely suspect. They're pretty easy to check. There are little screw in plugs in the valve cover to check them through, but it's so easy to take the valve cover off that bike it's usually better just to do that. Then you can see the cam to get it in the right position. You turn the crank till the cam lobe is pointed away from the valve and check the clearence. It should be about .002" for the intake and .004 for the exhaust. If it's more than twice that, there will be noise.
They're easy to check. Adjusting them is another story. You have to replace the shim between the cam and valve with a different thickness one, and they're almost impossible to find now.
Also make sure the cam chain is properly adjusted. If the cam chain tensioner is bottomed out, the chain needs to be replaced.

Answer 3

Yamaha Xs650 Engine

Answer 4

G B sound like he knows what he is talking about...if you do adjust the valves make sure the engine is cold....clearances change when hot....