FAQ: Trimmers

Read through our "Frequently Asked Questions" for information regarding basic operation and maintenance for Trimmers.

Trimmer Man Blue Shirt

Q: What is the Fuel-Oil mix ratio?
A: The fuel-oil mixture ratio is 40:1. You can obtain this ratio by mixing 3.2 oz. of two cycle air cooled engine oil with one gallon of regular gas. Over a period of time oil will separate from gasoline. To properly insure oil and gas mixture, we recommend thoroughly shaking your oil and gas mixture before refueling your unit.

Q: Why do I have to use a Fuel-Oil mixture?
A: All Poulan Pro two-cycle products require oil to be added to the gas. Unlike engines that have separate gas and oil reservoirs, two-cycle engines run on a gas/oil mixture that keeps the engine lubricated at all times. Never use straight gas in a two-cycle engine as straight gas will ruin the engine within minutes.

Q: What grade of gas should be used?
A: Our units run on 87 octane regular unleaded gasoline. You can use gasoline which is blended with a maximum 10% alcohol. Never use E85 or diesel fuels. Remember to use fresh gasoline and to mix it with the recommended 2-cycle oil.

Q: Can I use alcohol blended fuels in my unit?
A: Alcohol blended fuel (called gasohol, or using ethanol or methanol) can be used with up to 10% alcohol. BUT do not store the unit with this mixture. These alcohol blended fuels attract moisture and form acids which can damage the fuel system. Fuels with more than 10% alcohol can rob your engine of power and cause your engine to run erratic. Our engines are calibrated to run on 87 octane regular unleaded gasoline.

Q: Can I leave fuel stored in my unit?
A: No, fuel should not be stored in the unit. It is important to prevent gum deposits from forming in the fuel system. If the unit is to be stored for longer than 30 days - drain the fuel tank, retighten the gas cap, and start the unit and let it run until it stops.

Q: How do I start the engine?
A: Starting most two-cycle engines is quite simple. Use the procedure outlined in your operator's manual if it differs from the following:

  1. Move the choke lever to the full position.
  2. Hold or lock the throttle in the on position (the throttle must be held or kept locked until the engine is warmed up).
  3. If the unit has an on/off switch, move it to the on position (usually indicated by the symbol "I", not "O")
  4. If the unit has a primer bulb, depress it 4-5 times (the bulb should be at least 1/2 full)
  5. Set the unit on the ground
  6. Make sharp, brisk pulls on the starter rope until you hear the engine attempt to run. This should happen between 1-6 pulls, but no more than 6 pulls
  7. Set the choke lever at the half position and resume pulling the starter rope. The engine should start after 2-6 more pulls. If not, move the choke lever to the full position and pull the rope two more times. Return the lever to half choke and pull 3 more times.
  8. Once the engine starts running, continue to keep the trigger depressed and let it warm-up for 10 seconds, then move the choke to the off choke/ RUN position. Allow the unit to run 30 more seconds at RUN before releasing the throttle trigger.
  9. When the unit is warmed up, it should restart with the choke in the off position. If the unit is allowed to cool down, you may have to repeat steps 1-8.
Some units use a carburetor which does not require holding the throttle trigger. If your unit only has a START and RUN position on the air filter cover, use the following:
  1. Set the unit on a flat surface.
  2. Move the ON/ OFF switch to the ON position
  3. Slowly press the primer bulb 6 times
  4. Move the start lever to the START position
  5. Pull the starter rope handle sharply until the engine starts and runs
  6. Allow the unit to run for 10-15 seconds, then fully squeeze the throttle trigger to disengage the starting system

Q: Why won't the engine start?
A: Several things would make an engine difficult to start:

  1. Do you have a fresh fuel mixture? Make sure the fuel mixture being used is less than 90 days old and properly mixed at a 40:1 ratio.
  2. If you have an on/off switch- make sure it is on.
  3. A fouled or incorrectly gapped spark plug will also cause an engine not to start. Remove your spark plug and clean the electrode with a small wire brush. If the spark plug electrode is wet fouled with gasoline, replace with a new plug. The gap should be set at .025".
  4. If the air cleaner is dirty, clean it with warm soapy water and allow it to dry before reinstalling.
  5. Make sure the fuel filter is clean.
  6. If you smell fuel after following the starting procedure, assume the engine is flooded. Set it aside for 10-15 minutes to allow the fuel to vaporize before starting over. If after checking these items the unit will not start, there may be a more serious problem. An authorized service center will have to examine the unit.

Q: Why does the trimmer line break?
A: Trimmer line usually breaks because of line crowding. This occurs when the trimmer head is held too close to hard objects that can break the line such as brick, cement, rocks, or fencing. Keeping the line at full extension, and not crowding it, reduces line breakage problems.

Q: How do I change the trimmer line?
A: There are five ways to change trimmer line depending upon the style of trimmer head on your unit.

The first style has a locking tab on the side of the trimmer head that must be depressed while the lock ring is turned counter-clockwise. This will remove the cover and give access to the spool which can then be pulled out, rewound with the line (winding in the direction of the arrows on the spool), and re-installed.

The second style requires lining up the marks on the bottom of the spool tap/button assembly and firmly pulling straight out on the tap button. This pulls the spool assembly out so it can be re-wound and inserted back into the hub assembly.

The third style requires pushing in and down on the two locking tabs on the side of the trimmer head. This will remove the cover and give you access to the spool.

The fourth style of trimmer head is the Centrex. Remove the cap on the bottom of the head by unscrewing it. Remove the guide ring and remove the spool from the unit. Cut a 25ft length of line and insert one end into the center cavity of the empty spool. Feed the line into the spool, leaving 4-6 inches unwound from the center of the spool. Reinstall the spool, guide and cap, making sure the notch in the guide is facing away from the spool and the line is in the notch. 

The fifth style is the fixed line cutting head. This style cutting head uses a pre-cut piece of cutting line. After removing the worn line from the cutting head, insert the precut piece into the positioning tunnel leaving an equal amount out each side of the tunnel. The ends of the line can then be inserted through the exit tunnels. 

Cutting line or pre-wound spools are available at most retailers that sell Poulan Pro products.

Q: Why doesn't the trimmer head turn when I press the throttle?
A:The trimmer head will not turn on a gas trimmer if the drive shaft is not fully engaged or the flexible cable is broken. Follow the steps below depending on which model you own.

If you see two screws on the front of the engine – loosen these screws. If you have a non-clutched unit, firmly push the shaft toward the engine while pulling the starter rope slowly. If the unit has a clutch, the shaft must be pulled out and the flex shaft lined up with the clutch drum and re-inserted until it seats. Rotating the cutting head while inserting the shaft makes shaft engagement easier. Then, fully insert the shaft and tighten the nose cone screws.

If the throttle is mounted on the shaft, remove the screws that hold the throttle handle on and remove the handle halves- make sure to note the position of the cable and trigger in the handle. Once this is done loosen the clamp that holds the shaft in the engine and firmly push the shaft into the engine while pulling the starter rope slowly until it seats. Reverse the steps to tighten the handle.

If all else fails, check to see if the flex shaft is broken. If this is the case, you will need to replace the flex shaft itself.

Q: How do I remove the trimmer head on a blade capable straight shaft unit and install the blade?
A: If you own a trimmer that is designed to accept a blade, follow these steps: To remove the head, align the hole in the dust cup with the indention in the gear box casing. Insert a hex wrench into this hole and unscrew the trimmer head by turning it clockwise. Remove all washers above the trimmer head, but leave the dust cup on the unit. Next, remove the plastic shield. Next, install the metal shield by one of two methods, according to your gearbox. If your gearbox has threaded bolt holes, install the four screws through the bottom of the shield directly into the gearbox. If your gearbox does not have threaded bolt holes, place the screws through the top of the gearbox, through the shield, and screw them into the retention plate. Install the blade, the retention washer, cupped washer and the retaining flange nut. Finally, line up the holes in the dust cup with the indentation in the gearbox and insert the wrench. Tighten the retaining nut until it is very tight (turn the nut counterclockwise to tighten). Make sure all appropriate handlebars, straps, and warning signs are in place and properly used.

Q: What is the correct spark plug gap?
A: The spark plug gap on all products is .025-inch.

Q: What type of spark plug does the unit take?
A: The size of the plug varies from unit to unit. On trimmers, blowers and hedge trimmers is RCJ-8Y or RCJ-6Y. Follow the spark plug recommendation and replacement procedures in the operator's manual if you are doing the work yourself.

Q: How do I lubricate the driveshaft?
A: There are two ways of doing this, depending on which unit you own.

On a curved shaft unit, the drive shaft housing must be removed from the engine to give you access to the flex shaft. The shaft is then pulled out, wiped down, and Poulan Pro shaft lubricant applied. The shaft is then put back into the housing, and the housing is reassembled to the engine.

On straight shaft units, the gear box is removed from the lower end of the shaft by removing the screws. The shaft is then pulled out from the bottom and lubricated in the same manner.

Q: Where is the fuel filter?
A: All gasoline engines have a fuel filter on the end of the fuel line in the fuel tank. Poulan Pro recommends changing the fuel filter yearly. To remove the filter:

  1. Drain the fuel from the unit,
  2. Pull the filter from the tank through the gas tank opening and remove it from the line,
  3. Install the new filter on the fuel line and drop back in tank.

Q: How often should I clean the air filter?
A: The air filter should be cleaned every 5 hours. A foam air filter can be cleaned by washing it in warm soapy water. Then rinse in clean water and let dry. On gasoline edgers, add a few drops of oil to the filter before installing.

Q: How long is the warranty?
A: All gas-powered lawn and garden items (trimmers, edgers, blowers, and hedge trimmers) carry a 2 year warranty and 40V battery products carry a 4 year warranty against manufacturers defects when used for household purposes.

Q: What does the warranty cover?
A: The warranty covers manufacturer’s defects. Parts and labor are covered under the warranty. Some items that ARE NOT covered include; improper maintenance, old or stale fuel, rotating head parts or the use of accessories or part not specifically recommended by Poulan Pro. Please see your warranty statement in your operator’s manual for the full warranty statement.

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