my bws 100 smokes too much. It’s an old scooter, I know, but something can be done … i guess …
Local scooter shop don’t want to spend too much time on it, so i want to start repairing it by my self, and learn a bit of mechanic at the same time ?
What can i try first to reduce the amount of smoke … and the smell !!!
It goes on a bit, and off at various tangents, but the likely causes are covered.
To summarise, its likely to be (a) the quantity and quality of the 2-stroke oil, (b) the quality and timing of the spark, or © excessive quantity of fuel delivered (carburretion), probably roughly in that order of probability.
If the bore/rings are very worn, you’ll be down on compression which might cause less efficient combustion and consequent smoking, but you’d likely notice a significant loss of power before combustion deteriorated to that point.
Quickest fix to try is to fit a new spark plug. Then investigate the oil pump operation/better quality 2T oil/running premix, then clean the carburrettor.
You might have to clean (burn or boil in caustic soda) or replace the exhaust before any improvements you make elsewhere are effective, due to accumulated oil cooking off when the exhaust gets hot.