Help 300ex Ticking

[countypark]

I've put new rings, timing chain and adjuster in, and the engine still has a tick.

There was no play in the rod, either end. I've adjusted the valves to .003 clearance.

I've taken both side cases off and inspected the internal components visually and I didn't see any signs of wear or damage.

The sound seems to be coming from the top end but it is hard to tell for sure. I also took out the valves and cleaned the shafts and the holes. They worked freely in the holes.

This is on my neighbors sons quad, the sound came about during the end of the summer.

I've adjusted valves on many quads so I am pretty sure that I have these adjusted properly.

The only other time I ran into a tick like this was when we had a TT R which had a burr on one of the gears under the clutchside case. I didn't see any burrs on this quad.

It makes the noise all the time, clutch in or out, in gear or out.

ANY IDEAS!!! The kid is getting really bummed out.

Thanks

[300exOH]

Maybe a worn cam?
Also I was thinking the valve clearance was .004. I could be wrong. I do know that my 300 has been somewhat "ticky" since day one. Have you tried using a different oil. I switched from Valvoline atv oil to Mobile 1 and it's been much quieter. Hope this helps. Good luck.

[44oEX]

I can probably help you out. I was working on a 300 ex and I had the same problem. The valve cover is worn out and the rocker arms are moving side to side. It`s not much but it`s enough to make the ticking sound. if you don`t want to change the valve cover ( to expensive ) you could get a machine shop to take a little more off the cover and put in a brace washer betheen the cover and the rockers.

[TCracin440ex]

valve clearance is .004.....if your rocker arms are old and worn out i got a new set i put in my old 250x last year...they have maybe 2 hours on them...it could be the tappets on the rocker arm too....they could be worn out