Well guys i’m back again with this old motor. After issues all last few years with flywheel magnet delamination, bad CDI (after replacing almost everything) is running great and is now reliable BUT i feel like it’s a little too loud underway. This added rattle/vibration sound has only been there since my repairs last year. At higher RPM it’s just an added roughness/ticking/rattle over the smooth hum of the engine. It’s very slight (my wife doesn’t think it sounds bad) but i can’t let it go. My first thought is detonation- i’ve been burning through older gas that was only REC 87 to begin with. I use treatment but in all honesty one tank is 6 months old and the other probably 3. But even earlier in the year when the gas was newer i feel like the noise was still there. My other thought is some slight interference under the flywheel/pulleys…during my failed CDI nightmare i swapped the ignition and pulser coils with used ones off ebay. Maybe something is a little off. BUT I would think low rpm would make noise too. Last thing is maybe the timing is one notch off- i am usually pretty meticulous but i’ll check that too. I adjusted the valves last year so i don’t think it’s that. Maybe a small exhaust leak?(i did an acid flush maybe it ate thru a passage in a corroded area)? Maybe just a vibrating plug or component? I’ll get some newer higher octane gas, pull the timing cover off and look around and try to take a video. I guess it’s possible this is just the normal timing system noise and i’m just hearing the flywheel and tensioner ratcheting noise…just was expecting a clean smooth honda hum 
