The chain brake on a Poulan chainsaw is a critical safety device designed to stop injuries from kickbacks. A kickback occurs when the spinning blade suddenly bucks and comes back toward the operator. During a kickback, the chain brake activates and stops the saw blade from turning before it strikes the operator. The chain brake on every saw should be routinely inspected for wear or damage. Replacing the chain brake on a Poulan chainsaw is simple and requires only two tools.
Place the chainsaw on a sturdy work surface. Turn the two chain brake nuts on the right side of the saw counterclockwise with a 1/2-inch wrench until they are free of the chain brake mounting studs.
Grasp the chain brake and pull it directly away from the right side of the saw and over the chain brake mounting studs to free it from the saw.
Pull the handguard on the new chain brake fully back until it clicks. The brake is now disengaged.
Slide the new chain brake over the chain brake mounting studs and into position against the body of the saw, being sure the chain adjusting pin on the brake fits into the lower hole on the chain bar. Twist the two chain brake nuts clockwise onto the studs by hand until they hold the chain brake firmly against the saw. The guide pin in the saw must engage the hole in the chain brake.
Turn the blade adjustment pin screw on the front of the saw clockwise with a flat-head screwdriver while holding the chain bar up until all slack in the chain is removed, then turn the screw counterclockwise one turn. The chain should now spin completely around the bar easily, but without slack.
Turn the chain brake nuts clockwise with a 1/2-inch wrench until tight.