Always start your df engines on the rich side. If they havent been run for a while or are in a different climate richen it up 1/2 turn. A BVM engine will run poorly rich but won't run very long lean. By poorly i mean low max RPM.

I always richen my engines needle before a first start of the day. Make sure to let it idle until heat is comming out of the glow plug hole. (every time!) This means it has lubrication and is up to working temp. This gives you a chance to hear the engine. Never start it and immediatly go to wide open!

Keep it rich! Remember to have good smoke.
Dustin