Small Engines (Lawn Mowers, etc.): Kubota Engine, rich mixture, proper heat

Question
I have a 3 cylinder Kabota engine model # WG600. It runs great for about half hour then idles itself down to the point of not running. After standing for an hour it will start again, and run for awhile the idle it self back down to nothing again. I checked the plugs and on the back plug there is a lot of carbon. Changed them in within 30 minutes running it was full of carbon again. Help please.

Answer
Dear Debbie,

Re: Kubota 3 Cylinder with carbon deposits.  These carbon build-ups indicate a rich mixture or weak ignition.  Causes being misfiring, hard starting and hesitation.  Ensure that the spark plug has specifications for proper heat range.
Check to see if there's a clogged air filter and/or if there's a problem with the fuel system, or any of the engine controls systems.  Check also to see if there is any ignition system problems.

Hope this information is useful for ya.

Howard