How to Replace the Bar on a Poulan Pro Chainsaw
The chainsaw chain attaches to (and rotates around) the guide bar. The guide bar is made of laminated steel and has a groove milled around its outer edge to keep the chain aligned. It has a rotating sprocket on the tip, which reduces friction as the chain curves around it. Chainsaw bars will wear over time. The chain groove will widen, which will cause the chain to tilt and pull to one side when cutting. The tip of the bar (just behind the sprocket) is a common wear spot. The metal will wear faster in this area, resulting in a misaligned chain, which is prone to jumping off the bar. Dirt is the guide bar's enemy. When dirt gets between the chain and the bar, it acts like sandpaper, quickly wearing the chain groove wider.
Let's get started.
REMOVING THE BAR
1. Remove the side cover.
a. Loosen the two nuts securing the side cover to the saw.
b. Use a screwdriver to loosen the tensioning screw and release the tension from the bar.
c. Remove the nuts securing the side cover to the saw.
d. Verify that the chain brake is disengaged (unlocked).
e. Remove the side cover.
2. Remove the chain.
a. Slide the bar back (toward the rear of the saw).
b. Disengage the chain from the front sprocket on the bar.
c. Disengage the chain from the rear sprocket.
d. Remove the chain from the saw.
3. Remove the bar.
a. Slide the bar off the mounting studs and remove it from the saw.
INSTALLING THE NEW BAR
4. Install the bar.
a. Install the new bar onto the mounting studs.
b. Slide the bar back (toward the rear of the saw) as far as it will go.
REASSEMBLING THE UNIT
5. Reinstall the chain.
a. Install the chain onto the rear sprocket.
b. Align the chain driver links with the groove along the top of the bar.
c. Install the chain onto the front sprocket (on the bar).
d. Slide the bar forward to bring the chain into alignment.
6. Reinstall the side cover.
a. Install the side cover.
b. Thread the bar nuts onto the mounting studs to hold the side cover in place (leave the nuts finger-tight).
7. Tension the chain.
a. Grasp and raise the distant end of the bar and chain assembly (near the sprocket).
b. Rotate the tensioning screw to increase tension on the chain.
c. Periodically lift the chain away from the bar assembly and inspect the gap between the chain and the top of the bar. (You should be able to lift the chain slightly out of the groove in the bar, but not so far that an entire driver link is exposed.)
d. Rotate the tensioning screw to increase (or decrease) tension on the chain (as necessary).
e. Tighten the nuts to secure the bar and chain.