[Redrider89]

Hey all, long story short. Sold my 400 and bought a 450r instantally missed my 400 so i bought a 02 for $800. Runs awesome with no issues except at random there is a clicking or rattle noise coming from the motor atv at idle. As soon as you tap the throttle it goes away completely and will no come back till random other idle. I changed the oil and filter to see what was in there and nothing no a spec or medal or anything. Also changed the plug and adjusted the valves with no improvement. Timing tentioner pulled out and functions as it should. Any other ideas?

 

[SlammedRanger]

Could be wore rocker arms or shafts, or a wore out auto decompression mech. The rocker shafts were bad on my quad and it would do something very similar. If i reved it at all it would go away for a long time. Sometimes never come back till it dropped to idle or i re-cold started it. Mine also had no metal shavings in oil. But if the shafts are .001 out of spec it will tick like a sewing machine. My .02