Submitted by Paul Pavlinovich
  1. Open the needle valve two turns
  2. Close the choke plate on the mixer
  3. Open the fuel tap if you have one
  4. With your hand over the mixer intake slowly pull the engine through compression until fuel runs out of the mixer
  5. Pull the engine through compression hard and it will fire and run
  6. Slowly close the needle valve until the engine runs clean
  7. After the engine warms up open the choke plate a little - you may have to adjust the mixer again
To stop the engine, just close the needle valve.

Your engine might have a lever to advance/retard the spark, if it does, retard it to start the engine then advance it to the normal position after starting.