Good morning Mr. Leitinger and thanks for the comment sir.
Clean gas at start up has to do with the state the gasifier and char bed was left in at the last shut down . Good deep char and starting the fire on the charcoal and avoiding non chared wood with you starting flame .
Most of the startups I will kill my fans before pulling gas to the motor . The fans will pull about 2-4 inches of water on the system . The big gasoline motor is capable of pulling up to and beyond 60 inches depending on rpm , throttle setting and char bed density .
If the fan valve and fans are left on and pulling with the motor at the same time the motor will over power the fans very easily and be drawing air in at the discharge vs exiting it. If I kill the blowers and valve and pull just with the motor I can draw on the gasifier much harder
My start up procedures depends on many factors .
Knowing the state of the char bed. Good deep bed vs shallow and small .
The price and availability of petrol . Right now it is $1.83 a gallon . in the past it has been near $4 a gallon.
I think the main factor with my starting method will be how big a hurry I am in . There have been times when an hour could be worth several thousand dollars . ( hay on the ground and rain on the way ) but most of the time it is worth almost nothing , If I think there is fire in the gasifier I may drive on petrol until the gasifier kicks in .
The below video shows starting my ole tractor . I did start it on gasoline but used gasoline only a few seconds .