Tecumseh starts only with new plug

[evilone]

I have a Lawn Boy with a 4.5 hp Tecumseh LEV-100 engine, that I only use for about 10 minutes of trimming a week. I can only get it to start if I install a new plug (or one from another running engine, it will start but with some difficulty. Sometimes it runs smoothly sometimes rough. The next time it won't start (or fire) unless I use a new plug. Where do I start? Thanks

 

[Rivets]

I would remove the carb and give it a good cleaning.

 

[darkexphos1]

It could be a bad coil.