Some is exhaust leak and some is valve tapping. I adjusted them but it made no difference. On another note I got a timing light from my neighbor and checked it, it was off by almost half an inch. Before I checked it I took a q-tip and a little white paint to highlight the little crimp in the pulley (timing mark) made it much easier to see while checking. Strangely enough the motor does not smoke nearly as bad now that the timing is at 5deg. It was at about 18 to 20 before. Engine is still running a touch rich but better than before adjusting the timing. I also don’t have to pull the choke to start it every time now.