I have a bit of a problem with my 2002 300ex. After sitting for about a year I decided to get it up and running again. There had previously not been any problems until garaging it.

The first thing I did was take off the fuel tank and drain it completely. Next I cleaned the air filter and gave it an oil change. Now it has a rough time starting and will only hold idle for a period of time. I'm thinking perhaps the carb is gunked up or I have a fouled spark plug. Does anyone have any input in what else I should try?

 

Most likely the carb. If it won't idle, that indicates your slow (idle/pilot) jet got gunked up while is sat. After you reinstall the clean carb, readjust the fuel screw.