I'm perplexed by this ticking sound that comes from my engine- or a nearby area. I can't find the exact location and it ticks about 5 times a minute.- so it's not a constant ticking. But I will hear a tick, or a few ticks every now and then. I seem to get a tick when I hold the throttle at 1/10 open.

I'm running the highest grade fuel so it's not the pinging sound you may be thinking.
I just want to make sure this isn't something serious- anyone else ever hear a tick from their 400ex?

 

It could possibly be the exhaust changing temperature, but I'm not sure.

 

Or maybe when you let off the gas it's the carb. cables stopping(stupid- I know).

 

Have you checked your valve lash?

 

I think I know the occasional "ticking" you're talking about.

It's not the valve adjustment. Does it happen more often just after starting?

Not sure exactly what it is, but I'd bet it has something to do with the decompression system.