I have a 99 RM125 that I just had the cylinder replated on, and I also added a FMF SST pipe and silencer, but I am having a problem with detonation and losing power on top end. It only Knocks when I am riding it, it wont do it when sitting on the stand and being reved up! I dont know much about jetting so i am looking for advise on what to do from here. Also the plug is dark and dry on the porcelin but oily on the threads.
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