Rich on #2 and popping/backfiring

Not sure why #3 cylinder would be connected to the smog system... hmmmm anyway, make sure you remove all this junk and then up on the valve cover, connect a hose between the two large spigots over the reed valves or plug the spigots with black RTV. These must be closed off...

I did replace the #3 spark plug at the same time. Maybe that was the more likely issue. I did however check and see that the old plug was sparking. Dunno, maybe it wasn't sparking hot enough. One of the reed valves was stuck slightly open too. Don't know if that would cause problems.

Ok, #3 cylinder dropped out again during idle. But... I found an air leak in an interesting location that was causing the problem. The vacuum diaphram on the petcock had a tear in it which allowed air to go through a groove in the plastic part that is between the two rubber peices of the diaphram (groove allows diaphram to displace air in the petcock), through the tear and into the vacuum hose that actuates the petcock. I replaced the diaphram and that solved the problem. Just thought I would put that out there for anyone looking for an air leak.