Hey everyone im new to the forum but hope someone can help! I have a2003 Polaris Predator 500 that was a cheap craigslist find, i know what more can i expect. Lol anyways it was cheap and i have had good luck with previous fixer uppers before, Well when i got it the seller was original owner and the motor i was promised is stock. It looks like its seen its fair share of rides but he told me it was just idling rough and a little backfiring when it last ran but it hasnt been rode in almost a year. Well when i got there the filter was kinda ghetto and filthy and i assumed prob filter and carb rebuild. Well got it to start in about 2 minutes after getting home and noticed it was a little rough and after a ride up the street a few times a few backfires. I also noticed a loud ticking from the top end of the motor. well i didnt wanna run it much so i parked it did a little online research and decided maybe timing chain or something so i opened up the top and seen it was a little off time so i set timing and but back together, well it idles great and not backfiring but still knocking. Chain seemed very tight so id assume not stretched also ticking doesnt stop when revving like a stretched chain can it just gets lauder with the motor. so i drained the oil to find metal on the plug. not real fine but big enough to be worried. So today i pulled the whole top end off expecting to find a bent valve or some damage on the piston or something but valves look like they have a lot of carbon but no pitting to be found and luckily piston looks great! the only metal i found was under one of the buckets where the shim goes was sever shards, the other three where clean? well thats all i know and hope i can get further advice asap. Thanks for reading this long post just trying to be as descriptive as possible, im fixing to take our the oil filter and give it a look while im waiting on some expert advice lol Thanks guys!