Guys my MC18 kinda make a tapping sound specially at idle.. I hear it came from the RC Valve so to be sure, I touched the RC Valve shaft and its positive that it is coming from the RC Valve. so I took it off and look at the Shaft and the RC Valve.. I noticed that it has a little play between the shaft and the valve itself. I dont think that the piston is hitting the rc valve causeif it does it should have cracked the piston by now and siezed the engine. the fact is the bike runs well except for that tapping sound.. is this normal for a 15000 KM engine and if its not what should I do? replace them? if I will not replace them what will happen?

Thanks a lot to all..
ride safe.

I've had this a few times when the shaft has worn and has a bit of slop. It's worth replacing the shaft 'cos valves that move about are potentially disaterous. The minor problem is that the exhaust timing will be constantly wriggling about as the valve position fluctuates. The major problem is when the play gets enough to catch a ring and BOOM!!!

Matt,

Does Tyga have this shaft? how much? if I will just keep the valves open.. will it run like s**t?

Yes, pinning the valves wide open will make it run like s**t down below about 8 grand.

You need to pull them out and have a look to see which part is worn and then try to replace with either new or good used bits.

The shaft was available separately on the MC18 (14211-KV3-000, R2J & R4J, 14211-KV3-770, R5K) but I don't know if it's still possible to buy it.

We don't have new shafts, and I don't have any used 18 valve/shaft assemblies that I can think of.

Maybe some other blokes out there can help.

Thanks matt, I'll try to look at some used parts store.