D.Lee,

In my limited experience, intermittent fuel problems are much more prevalent than a intermittent ignition problem. It's a simple matter of squirting some fuel down the carburetor next time this happens to see if it gets the engine going for a second or two. If there is any question about the fuel supply, a temporary little can of gas attached to the suction side of the fuel pump will eliminate the tank and line from tank to pump.

If you can narrow it down to fuel or ignition, you can proceed with vigor...I vote for fuel.

Stuart