Intake. The fuel/air mixture is first drawn into the crankcase by the vacuum that is created during the upward stroke of the piston. The illustrated engine features a poppet intake valve; however, many engines use a rotary value incorporated into the crankshaft.
3. Is the guide bar and chain assembled correctly? Check out the ‘Removing/Replacing the Guide Bar and Chain’ section in your gas chainsaw manual. 4. Is the chain installed right? Make sure the cutters are positioned in the proper direction to cut. If the chain’s installed backwards, it makes cutting wood difficult.