Just pulled my Stihl Edger out for the season and found some problems. Wouldn't run properly so in goes a carb kit, new plug and made sure I was running fresh fuel. Unit starts right up then dies after idling for 2 or 3 minutes. Then it won't start or is next to impossible to start again. Unit is only 2 years old with approx. 10 - 15 hours use max. Any ideas?