How to Properly Operate a Drag Saw

By Staff

Starting your drag saw

Fill the water tank three-fourths full with clean water and the gas tank with a mixture of gasoline and a good grade of motor oil. This mixture should be 1 pint of oil to every 5 gallons of gasoline. DO NOT put too much oil into the gasoline, or it will affect the operation of the motor.

Remove the pipe plug from the topside of the crankcase, and in its place install a drip oiler. It should be set to deliver 15-20 drops per minute. If the saw has not run for a while, you should add a 1/2 cup of oil into the crankcase to make sure everything is well-lubricated. After it has been running for a while, drain the oil out of the crankcase. For future running, use only the drip oiler. Fill all grease cups with a good grade of grease and screw down tightly. These grease cups should receive frequent attention at all times.

Set the machine up on a log. Make sure that the handle on the guide rods will clear the log as the saw blade sinks into it. Then drive the dogs deep into the log, making sure they are also tight against the side of the frame. Make sure that all bolts are tight and that the saw blade is securely held on. Before starting the saw, make sure the clutch is disengaged. The clutch, guide rods and saw plate or cross head should be supplied with plenty of oil at all times.

Always stand on the left side of the machine, not on the side of the saw blade. When starting, take hold of the flywheel with your right hand, and grasp it around the flywheel rim. Rock the flywheel back and forth with this hand while placing the palm of your left hand over the air intake on the fuel mixer. This causes a rich mixture of gas to be drawn into the motor and makes starting easier. Never do this when the motor is hot, however, or it will choke and stop running. Rock the flywheel back against compression and let go. Keep doing this until the engine starts. On some drag saws, it is necessary to turn the flywheel by hand all the way through the compression stroke for it to start. When facing the flywheel of the motor, it should be turning to the right while running.

Running your drag saw

After the motor has started, advance the timing of the spark. Then lower the blade onto the log, and while increasing the speed of the machine, open the clutch and the saw will be in operation. To increase the speed of the engine, you have to advance the spark. When the cut is almost done, slow the engine down by retarding the spark. When the cut is finished, release the clutch, raise the saw blade drive up, and place it into the holder mounted on the frame.

If the motor starts in the wrong direction (turning to the left when facing the flywheel), this is caused by having the timing set too far advanced. Care should be taken not to get too rich of a mixture of gasoline by opening the mixer valve too far, especially if your motor is hot, as this will choke it and cause it to die. This can usually be detected by listening to the engine firing. If the fuel mixture is right, the explosion will be smart and sharp. If it is too rich, the sound of firing will be muffled. If the explosion blows back into the mixer, you will know that the mixture is too lean, and the fuel valve should be opened a little bit more.

The motor can be primed by holding your hand over the air intake on the mixer while you rock the flywheel back and forth. This should only be done when the engine is cold, to make starting easier. If you get too much gasoline into your motor, it will be necessary to take the spark plug out and turn the motor over several times to work out the rich mixture.

When your chain stretches and gets loose, loosen the bolts on the bearing and slide the bearing back until the desired tension is secured. Make sure that both bearings are in line and then tighten the bolts.

Maximize performance

To get the most out of a drag saw blade, it must be kept properly set and sharpened. This results in better, easier and nicer sawing. This also helps the engine’s economy and results in longer saw-blade life. While in operation the blade will acquire gum, pitch or sap. It should be kept free of this with kerosene. Kerosene is applied to the blade by either rubbing it on, or squirting it on the blade from an oilcan. The saw should be run at approximately 60 revolutions per minute. This makes 120 outs per minute as the blade of a drag saw cuts equally on the pull and push strokes.

Drag saw don’ts

– Don’t prime the motor by putting gasoline in the spark plug hole, as this will wash the oil off the cylinder walls.
– Don’t race the motor when running in idle.
– Don’t prime the motor when it is hot.
– Don’t leave water in the motor in freezing weather.
– Don’t let pitch pinch the saw blade while cutting. Pouring kerosene into the cut can prevent this.
– Don’t fail to oil and grease machinery regularly.
– Don’t use a hammer to remove the flywheel since the crankshaft is made of high tensile metal, which is easily damaged by a sharp blow. Instead, take the flywheel to someone with a press and have them press it off.
– Don’t tighten the nut on the end of the crankshaft so tightly that the clutch collar will not turn. The collar should be able to turn without rubbing.

Contact Chris Jerue, Cheney, WA;

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