How To Replace The Oil Pump On A Chainsaw
This blog provides common repair instructions for replacing the oil pump on a chainsaw. The most common reason for replacing the oil pump is when the cutting chain does not run smoothly.
Before you start this repair, you’d better make sure the engine has cooled and that the on/off switch is in the off position.
Step 1: You need to use a wrench or a 13 millimeter socket to help loosen and unthread the nuts securing the clutch cover. You also want to confirm that the chain brake is disengaged and remove the cover.
Step 2: Next, lift off the front chain guard then remove the cutting chain and bar.
Step 3: Now unthread the knobs securing the air filter cover and pull it off. Remove the wire and boot from the spark plug, and use the wrench to help loosen the spark plug, then take it off. Confirm that the piston is in the down position, then insert a cord into the cylinder to prevent the piston from moving.
Step 4: Use a large flat head screwdriver and strike it with a hammer to rotate the clutch clockwise to unthread it from the crankshaft. Pull off the clutch drum and sprocket assembly and the remaining washer. Use a small flat head screwdriver to bend the retaining tab to release the rear chain guard.
Step 5: Remove the screws securing the oil pump and cover by using a t15 Torx bit screwdriver. Pull the pump and cover off, then detach the oil block intake hose. Next, use pliers to remove the hose coupler then pull out the oil pickup tube, and remove the gear spring.
Step 6: You are now ready to install the new oil pump. Slide the new gear spring onto the crankshaft. You can use a large flat head screwdriver and hammer to help push it into place. Now insert the new oil pickup tube into the casing and press the new hose coupler into place. Then insert the seal into the new pump cover, slide the oil block onto the pump and attach the intake hose to the coupler. Position the pump cover and align the oil block in the groove on the casing, then rethread the screws to secure the cover. Slide the rear chain guard onto the chain bar mounting posts and slide the rear washer onto the crankshaft, then replace the clutch drum and sprocket assembly along with the inner drum washer. Rethread the clutch counterclockwise onto the crankshaft then tighten it. Remove the cord from the cylinder, rethread the spark plug and be careful not to strip the threads by over-tightening. Reattach the wire and boot, realign the air filter cover and rethread the knob to secure.
Step 7: Realign the chain bar on the mounting posts and align the chain on the sprocket and the chain bar. Make sure the teeth on the chain are facing towards the front end of the chain bar on the top and away from the front end on the bottom. Reposition the front chain guard to replace the clutch cover. The chain tensioner pin will need to be inserted into the hole in the chain bar. You will probably need to rotate the tension adjustment screw counterclockwise to properly align the tensioner pin. With the cover in place, hand-tighten the nuts. Now lift the bar and rotate the adjustment screw clockwise until there is no slack in the chain. Fully tighten the nuts and confirm that the chain is taut.
With the repair completed, turn the on/off switch to the on position and your chainsaw should be ready for use.
Please let us know if this works and if you have any suggestions or comments. Or you can join HIPA DIY COMMUNITY to feature your passion for repair projects, share your stories with the Hipa family and get help from Hipa.