JD14 cylinder missing - sometimes

I have a JD 14 that has a nearly new Honda GX690 engine. Yesterday it started running rough. After a bit of testing I figured out one spark plug wasn't firing. As I was tinkering it started running properly and ran fine until I worked for about a half hour today. All of a sudden it started running on one cylider again. A few minutes later it went back to running smooth. I checked the spark plug wire and it appears to be connected correctly.



Any ideas?



Thanks in advance.

JD14 cylinder missing - sometimes