jvon
11-17-2011, 09:05 PM
I have a yamaha 2008 big bear 400. I just bought it and put new rings, over sized piston and new timing chain. When I start the atv it sounds fine about 20 secs after running it starts to make a tapping. The tone changes with rpms, it seams a little louder at idle. Any help would be great. Set intake valves at .004 and exh. at .007