Honda GL1100 interstate Owner's Manual page 89

Problems which may affect Motorcycle Emissions
If you are aware of any of the following symptoms, have the vehicle inspected and
'repaired by your local Honda Motorcycle Dealer.
. Hard starting or stalling after starting
Rough idle
. Misfiring or backfiring during acceleration
. After-buming (backfiring)
. Poor performance (driveability) and poor fuel economy