the chain won’t oil at all, i see no fling on the bar even with the adjustment screw all the way open

Diagnosis

The Milwaukee M18 Fuel 16-inch Chainsaw (2727-20) utilizes a pressure-driven automatic oiling system that is highly sensitive to debris. When you see zero oil fling on the bar despite the adjustment screw being open, you are likely dealing with a "paste clog." This occurs when fine sawdust mixes with the bar and chain oil, creating a thick, viscous sludge that settles in the oil discharge port of the pump housing or the narrow oiling channel of the guide bar. Another common cause is an air lock within the oil reservoir. If the saw was stored on its side or if the oil level dropped too low, an air bubble can prevent the internal pump from priming. You can confirm the root cause by removing the bar and chain and running the motor at full throttle; if oil does not spray from the pump outlet onto the chassis, the blockage is internal or the pump is air-locked. If oil sprays freely but doesn't reach the chain, the blockage is located within the bar's oil hole or the bar pad interface.

How to Fix It

Follow these steps to clear the oiling system and restore lubrication:

1. Power down the tool and remove the M18 battery to ensure safety.
2. Remove the bar nuts and slide the guide bar and chain completely off the power head.
3. Locate the oil discharge port—the small hole where oil exits the pump to enter the bar. Use a thin piece of flexible plastic tubing or a compressed air nozzle (set to 30 PSI) to blow directly into the port to clear any sawdust paste.
4. Inspect the guide bar's oil hole. Use a small pick or a 1/16" drill bit (by hand, do not power drill) to clear the oil channel. Ensure the hole is completely open and not glazed over with dried resin.
5. Reinstall the bar and chain, ensuring the bar is seated firmly against the chassis. Tighten the nuts until the bar is snug but not pinched.
6. Insert the battery and run the saw at full throttle for 30 seconds without cutting any wood. This "primes" the pump and forces oil through the chain.
7. Check for "fling" by running the chain at full speed near a light-colored stump or a piece of cardboard; you should see a distinct spray pattern of oil droplets.

If That Didn't Work

• Check the Oil Tank Vent: If the vent in the oil cap is clogged, a vacuum forms inside the tank, preventing oil from flowing into the pump. Clean the cap with a solvent or try running the saw with the cap slightly loosened to see if oil flow returns.
• Verify Oil Viscosity: If you are using a heavy-grade winter oil or a low-quality resin-heavy oil, the pump may struggle to push it. Drain the tank and refill with a high-quality, low-viscosity bar and chain oil specifically designed for electric saws.
• Inspect the Bar Pad: Some aftermarket bars or worn-down pads create a gap between the pump outlet and the bar's oil hole. Ensure the bar is perfectly flush; if there is a gap, the oil will leak onto the chassis instead of entering the bar.
• Pump Replacement: If the pump makes no noise and no oil exits the port even after cleaning and priming, the internal gear pump may have failed. This requires a teardown of the motor housing to replace the oil pump assembly.

Heads Up

• Never run the 2727-20 without oil; the high RPMs of the Fuel motor will overheat the bar and stretch the chain in minutes, potentially ruining the guide bar.
• Clean the oil discharge port every 5-10 tanks of oil using compressed air to prevent the "paste" buildup from returning.
• Always use a dedicated bar and chain oil with a tacking agent; using standard motor oil or WD-40 will degrade the pump seals and fail to lubricate the chain effectively.
• Check your chain tension frequently; a chain that is too loose can actually disrupt the oil film on the bar, making it appear as though the saw isn't oiling.