4 Stroke engine muffler issue.

[SpeedingTurtle]

So I'm trying to put the exhaust on and unlike the engines in many of the tutorials I see, there are these stock bolts that comes out. I'm not sure if I can remove them.

Edit:

HuaSheng 49cc 4 stroke engine

 

[curtisfox]

They are studs, you can double nut them and then they should come out. Jam one nut against the other so it will lock them on the stud, then turn them out, using inner nut...........Curt

 

[MotorBicycleRacing]

5mm studs or you can replace with allen heads.
You could grip the unthreaded section with vice grips but double nutting is better.

 

[SpeedingTurtle]

The double nutting worked! Thanks guys!