I am lost...I got this knocking sound in my engine at idle..and can not locate it. The set up..Recently I bolted on a FMF Gnarly pipe and Turbine Core 2 silencer on my 99 KDX 200 (stock Jetting). While out on a seventy mile ride I noticed around mile 60 this knocking .pinging. I thought my pipe may have been loose or the pipe guard. Got it home tightened up all the bolts still hear it. I bought the bike used and just started to ride it hard after a year..so I did a top end job..and added boyesen power reeds.Still got the sound. Changed the Gas (Ultra 94 and H1R at 40:1) and plug. Cleaned air filter .carb. still got it..Is it possible this sound is coming from the water pump..The vibration seems the strongest there when I put my hand on it. The manual says check the CDI and ignition timing..I'll be doing that today...Any ideas. I already sat out one race due to this noise, don't want to miss another. Any replies appreciated.