Motorcycle Repair: Problems with Suzuki GN125, air fuel mixture, suzuki gn125

Question
I have a suzuki GN125. Whenever I stop the bike after riding for over 5-10 minutes there is always a loud bang/pop from the exhaust. It does not appear to be affecting the performance of the bike in general. Also the bike takes longer to start after riding than from cold. What is causing these problems and would I be able to resolve them myself?

Answer
Hi Andrew,

The bang when turning off the engine is a result of ignition timing, compression, and unburned gasses in the exhaust and cylinder. The sound occurs because not all of the fuel mixture is burned on that last cycle of the engine and then a spark is produced to ignite the mix in the pipe. It's not uncommon and shouldn't cause any damages.

Hard starting after warm is due to how the air-fuel mixture from the carburetor reacts with the hot combustion chamber. Again, compression and timing come into play.

If possible, check and adjust the ignition timing. If your GN has CDI or TCI ignition, it cannot be adjusted. Older MC's used adjustable breaker points.

Respectfully,
Mark Shively