Old scooter? Smell?

I don’t know why things stink you keep away from it. Just like you don’t eat things that taste funny. Evolution gave us the senses to warn us about dangerous.

Engine exhaust gases are harmful, that should be known.
Even if Diesel Dieter is right and no birds fall from the sky on his way of shopping once a week, such environmental pollution is not good for a long time.

If you have a two-stroke scooter, it’s even very normal that you’re running.
There, oil is added to the fuel to lubricate the engine. This is burned.

Also, the mixture could not be ideal, so that the fuel does not burn so cleanly. Otherwise, it is not possible to do much.