Slipping in and out of 2nd gear poses a problem for a lot of motorcycles. Throttle happy riders who make hard, redlined shifts from first to 2nd cause a lot of wear.
It indicates a motorcycle with a PAIR or other secondary air injection system on it. Gasoline combustion is never 100% in motorcycles or automobiles. There are always going to be unburned hydrocarbons in the exhaust. With the presence of an air injection system allowing oxygen into the exhaust port during the exhaust stroke, this creates extremely high temperatures in the port, allowing for ...
Motorcycles are an oddity to most people, they don't understand why someone made of flesh and bone would whiz around on a machine capable of insane speed but is equipped with no roll cage, no airbags and no coffee cup holder.