Yfm 225 top end noise and reliability
 

Hi all, this is my first post on here but I've been reading this forum for about 5 years. Anyways I bought an 86 moto 4 this winter and it is very fun. The previous owner decided to rewire the entire electric system after many things went. It's a moto 4 225s (the s is the model of the 225 moto 4) and if anyone is wondering the cc in their own moto 4 I know a good website to visit and you can just search up the motor's serial and it will tell you which motor and which bike. It was used as a hunting camp bike up until I bought it with an ownership for 550 bucks. It runs and drives perfectly fine and I love it, so much fun. When I bought it I heard a small amount of noise from the top end, not unusual for a bike that old. Recently it has been getting much worse and I'm starting to get concerned if it's something I can fix easily or if I can just tighten/rebuild something in my own garage. It's sort of a clunking and ticking noise so one of those could possibly be the connecting rod but it sounds more like it's coming from the top end. It has only lost a tiny bit of power but it's not that noticeable, I've ruled out it being the cam chain and the valves as I have adjusted them to spec. I am wondering if this top end noise is common or not in these bikes and if anyone could let me know if it's an easy fix or if I should drop the money to have a trusted mechanic rebuild it. The odometer isn't currently working, so I have absolutely no clue to the kilometers on the bike. I love the bike and would hate to have to get rid of it so any help is very much appreciated. Thanks for looking.