These are my rambling "carb thoughts" when contemplating a startup.
Thinking in terms of what the fuel's doing, has been doing, and will do.
When sitting cold, carbs cold, fuel cold, difficult to vaporize fuel, use choke.
After a significant, fully heated ride, carbs are hot and will heatsoak from neighboring engine heat, making them hotter. Hot fuel vaporizes readily when hot, and will give the effect of overrich.
If a short pause, still hot, carb throat full of fuel vapors, crack throttle for restart, or fully open throttle and kick with ign off to clear the vapors.
If a longer pause, and engine is just warm, the vapors will still be in there, and starting to condense. Anticipate an overrich startup, crack throttle, or clear it.
If an even longer pause, and engine temp is close to ambient, vapors probably gone, but may have condensed fuel in the throat. Clearing may not be necessary, but immediately crack throttle after kick to clear the condensation.
After a short/mild, warm-up ride, engine and carbs not hot, not worried about hovering vapors and overrich. Start normally.
If start fails after the hot run, suspect fuel fouled plug(s). Do the clearing thing. An old trick to get spark to fire thru fuel foul, pull the plug caps just enuff to have a 1/8"-1/4" gap between the sparkplug's post and the plug cap's connector, forcing the spark to "jump" the gap, which induces a higher initial spark voltage in the plug's gap, firing thru the foul. The foul-blasting "spark gap" contraptions are based on this old racer's trick...
Thinking in terms of what the fuel's doing, has been doing, and will do.
When sitting cold, carbs cold, fuel cold, difficult to vaporize fuel, use choke.
After a significant, fully heated ride, carbs are hot and will heatsoak from neighboring engine heat, making them hotter. Hot fuel vaporizes readily when hot, and will give the effect of overrich.
If a short pause, still hot, carb throat full of fuel vapors, crack throttle for restart, or fully open throttle and kick with ign off to clear the vapors.
If a longer pause, and engine is just warm, the vapors will still be in there, and starting to condense. Anticipate an overrich startup, crack throttle, or clear it.
If an even longer pause, and engine temp is close to ambient, vapors probably gone, but may have condensed fuel in the throat. Clearing may not be necessary, but immediately crack throttle after kick to clear the condensation.
After a short/mild, warm-up ride, engine and carbs not hot, not worried about hovering vapors and overrich. Start normally.
If start fails after the hot run, suspect fuel fouled plug(s). Do the clearing thing. An old trick to get spark to fire thru fuel foul, pull the plug caps just enuff to have a 1/8"-1/4" gap between the sparkplug's post and the plug cap's connector, forcing the spark to "jump" the gap, which induces a higher initial spark voltage in the plug's gap, firing thru the foul. The foul-blasting "spark gap" contraptions are based on this old racer's trick...