Rossi: Death and taxes - Understanding how 'step-up in basis' works. An IRS building in a file photo. It is often said the only certainties in life are death and taxes. Thanks to estate and inheritance tax, it is not uncommon for them to occur simultaneously.
Probable Causes: An engine that hesitates, stumbles or misfires when accelerating or when it is under load, is an engine that is either sucking too much air, not getting enough fuel, or misfiring. If there are no misfire codes, a common cause of acceleration stumble is a bad throttle position sensor (TPS).
In general, backfiring on deceleration (as opposed to acceleration) is generally caused by a lean condition in the pilot circuit. What happens is that the mixture leans out enough to where is fails to ignite consistently. This, in turn allows some un-burnt fuel to get into the exhaust pipes. Then when the engine does fire, these un-burnt gasses are ignited in the exhaust pipe, causing the backfire. Newer Virago carbs have an 'enricher circuit' which cuts in on deceleration to help this problem. Earlier carbs do not have this.