Honda trx350 Foreman engine tick and idle issues

Ok, I got the foreman put back together. Had the tank redone, cleaned the carb, and it idles like crap. Runs like crap from idle to 1/4 which sounds like pilot jet, but the venturi and jet are not plugged. Almost acts like it is rich, black smoke from the exhaust till you rev it and it is fine. Tried adjusting the pilot screw, makes no difference. I took the carb down to the dealer and it looked fine to the mechanic.

Also, I here an intermittent rattle, can't tell where it is coming from, sounds like in the top end somewhere. Valves and rockers look good, it isnt a consistent tick like a valve lash issue. Stretched timing chain? Anyone have experience with these things? Not sure why they did the dual valves thing on this small of an engine. Any help appreciated. Thanks