Well well,if your running rich you should see black marks around exhaust tip,also blackened spark plugs,
Your running lean,car or bike wont accelarate like old times.accelaratiion might be flat.
İf you are wondering about duke 390.have checked the ecu.ktm dealers should have a computer to check that.
Back in old times when engines were carburated,you had to adjust from time to time.
Nowadays ecu handles that
When tuning a bike for the first time, it may be difficult to figure out if your bike is running too rich or too lean. Both conditions can be very harmful to yo