Spit Mark IV Backfires!

[Mike Brinker <mbrinker@flash.net>]

Hello All,

My friend has a Mark IV Spitfire that has a single stromberg carb on
it.  The car seems to run ok but when he shuts off the engine, the car
backfires!  I think it might be the carb being set to rich.  What do you
think.  It seems to do it more when the car is warmed up, not on a cold
start and then shut off.  Timing, carb adjust, anti-run on......Help?

Mike Brinker....Helping out a friend