well you might have several things going on with your bike.
1. You may need to remove the carb and do a complete clean job.
2. Your using cheap 2 smoke oil and using inconsistant fuel/oil mix. If you don't have the mix-rite cup go get one trust me it's worth it and you may be using watered down fuel so replace it with fresh fuel if needed.
3. What color is your plug tan, brown, black, or white/greyish? If your bike is running to rich fudge brown or black then you should replace it. It's ok to run rich but not to rich it just fouls the plug. Keep in mind the weather has changed so this cold air will cause the bike to run a bit rich so you may want to lean out a touch.
4. Check your bas gasket to see if oil is leaking around the bottom of the cylinder if so replace it.
5. Check you intake gaskets this will cause hard starting. Your carb gasket may be shot or the intake manifold itself has a crack from vibration.
6. check your spark as the coil may be bad.
7. last if your able to pull the pull start with very little resistance then I would check the rings..
Hope all this helps it did for me.
