Craftsman 358791820 trimmer Parts

The Craftsman 358791820 gas line trimmer uses 0.080 inch (2 mm) diameter round cutting line. For safe operation and proper line advance, we recommend sticking with the specified round line and following the line-loading steps in the 358791820 operator's manual.

Use these specs for the trimmer head on this model:

• Diameter: 0.080 inch (2 mm)
• Shape: round
• Material: trimmer cutting line only (not wire, rope, or household string)
• Typical refill length: 25 ft (8 m) when winding an empty spool

Using the correct 0.080 inch round line helps the bump-feed system advance line properly and keeps the cutting head working as designed. Oversize or non-round line commonly causes poor feeding, extra vibration, and premature wear on the spool and cap.

We follow the same basic process outlined in the manual:

• Cut 25 feet of 0.080 inch round line.
• Feed the line into the spool and wind it in the direction shown on the spool.
• Leave about 4 to 6 inches of line free before reinstalling.
• Thread the line through the guide ring and reinstall the cap securely.

If you need a complete parts breakdown for the cutting head (spool, cap, guide), use the diagrams and instructions in the 358791820 operator's manual.

Last updated: February 2026

To replace the cutting line on your Craftsman gas line trimmer model 358791820, remove the trimmer head cap, lift out the spool, then install a pre-wound spool or rewind the spool with 0.080 inch (2 mm) round line and reassemble the head so the line feeds smoothly.

• Stop the engine and let it cool.
• Disconnect the spark plug wire before maintenance.
• Wear eye protection and hearing protection.
• Clean dirt and grass from the cutting head so parts seat correctly.
• Use only 0.080 inch (2 mm) round line; never use wire, rope, or string.

1. Hold the spool housing and unscrew the cap in the direction shown on the cap.
2. Remove the line guide ring and lift out the spool.
3. Choose one method:
   • Pre-wound spool: remove any tape strip holding the line.
   • Refill the spool: wind 0.080 inch line neatly and evenly so it does not cross over itself.
4. Feed the line ends through the eyelets/guide in the line guide ring.
5. Reinstall the spool and line guide ring, then tighten the cap securely.
6. Start the trimmer; the head advances line automatically to the correct cutting length.

• Wind the line in smooth, tight layers; do not overlap or crisscross.
• Keep both line ends the same length.
• Do not overfill the spool; leave room for the line to move.
• Keep the shield installed; it helps maintain proper line length.

Correct line size and neat winding prevent jams, poor cutting, and premature wear. This model is designed to advance line automatically; tapping the head can break parts and cause the cutting head to malfunction.

For diagrams and model-specific details, follow the instructions in the 358791820 owner's manual.

Last updated: February 2026

For the Craftsman 358791820 gas line trimmer, fuel line size depends on whether you are replacing the small return line or the larger supply line. Use the routing and connection points shown in the 358791820 owner's manual to match the correct line to the correct fitting.

Most 2-cycle trimmers use two different fuel line diameters:

• Small line: commonly about 1/8 inch OD with about 3/32 inch ID (often used as the return line)
• Large line: commonly about 3/16 inch OD with about 1/8 inch ID (often used as the supply line)
• Lines must fit snugly through the tank grommet and onto the carburetor fittings to prevent air leaks
• Replace lines that are soft, cracked, swollen, or leaking

If you are replacing lines on this model, we list both a small and a large fuel line option:

• Compare the new line to the old line (if available) for OD and ID
• Test-fit the line on the tank fitting/grommet and carburetor nipple; it should be tight without forcing
• Route the line exactly as shown in the manual so it does not kink or rub
• After installation, check for fuel seepage and air leaks before running

A fuel line that is even slightly loose can pull air into the fuel system. That causes hard starting, surging, stalling, and lean running that can damage the engine over time.

Last updated: February 2026

The Craftsman 358791820 is the model number for this gas line trimmer; in the operator documentation it appears as 358.791820 (same model, different formatting). Use 358791820 when searching for Craftsman parts like a carburetor, fuel line, or recoil starter. See the 358791820 operator's manual.

We recommend confirming the tag on the unit so you match the correct parts list.

• Check the model/serial label on the shaft near the handle area
• Look for a label near the engine housing or starter cover
• Match the number to the manual cover page (often shown with a dot format)
• Use the full model number when ordering parts (no spaces)

These are equivalent identifiers for the same Craftsman trimmer.

Craftsman trimmers can look similar across years and engine sizes; the exact model number ensures the right fit for engine parts and fuel system items. For example, the correct carburetor and fuel line routing depend on the exact parts breakdown for model 358791820.

• Fuel line sizes (small vs large)
• Carburetor and carburetor adapter
• Recoil starter components
• Piston kit and piston ring

If you are replacing fuel lines, match the sizes listed for this model, such as ayp lawn & garden equipment fuel line, large 530069216 and poulan lawn & garden equipment fuel line, small 530069247.

Last updated: February 2026

Craftsman gas trimmers are sold under the Craftsman brand; the brand is owned by Stanley Black + Decker. For your Craftsman model 358791820, the exact factory that built the unit can vary by production run, but parts, service procedures, and specifications are supported through the model’s documentation.

The most reliable way to match parts and service info is to use the model number and the parts list in the documentation.

• Confirm the model number on the trimmer’s ID label matches 358791820
• Use the parts list and diagrams in the 358791820 operator’s manual to match assemblies and hardware
• Follow the manual’s safety steps before any service (for example, disconnect the spark plug before maintenance)
• Use the specified cutting line size (the manual calls out 0.080 in (2 mm) line)
• Use the correct fuel mix for this 2-cycle engine (the manual specifies 40:1)

For repairs, the “maker” matters less than using the correct model-based parts and procedures.

If you are troubleshooting fuel delivery issues (hard starting, stalling, won’t stay running), these model-matched parts are commonly involved:

• Ayp lawn & garden equipment fuel line, large 530069216 (fuel supply line)
• Poulan lawn & garden equipment fuel line, small 530069247 (return or primer line, depending on routing)
• Line trimmer carburetor 530071811 (metering and fuel delivery)

Using the correct model-specific documentation prevents mismatched parts and unsafe adjustments. It also ensures you follow key safety rules (fuel handling, ventilation, and spark plug disconnection) that reduce fire risk and injury.

Last updated: February 2026

For the Craftsman 358791820 25cc 2-cycle 17-inch trimmer, we use fresh unleaded gasoline mixed with a good-quality synthetic 2-cycle air-cooled engine oil at a 40:1 ratio (3.2 oz oil per 1 gallon of gas). See the 358791820 owner's manual for the exact fueling and safety steps.

Use this chart to mix the right amount every time.

Using the correct oil protects the piston, rings, and crankshaft from rapid wear.

• Use synthetic 2-cycle oil labeled for air-cooled engines
• Use oil intended for 2-stroke outdoor power equipment
• Do not use automotive (4-cycle) engine oil
• Do not use marine or boat 2-cycle oil (water-cooled formulas)
• Mix fuel in an approved fuel container; then shake briefly to blend

Old fuel is one of the most common causes of hard starting and poor acceleration on gas trimmers.

• Mix only what you will use in about 30 days
• If storing 30 days or longer, drain the tank and run the engine until it stops
• Use fresh 40:1 fuel at the start of the next season
• Consider fuel stabilizer if you expect fuel to sit; follow the stabilizer label directions

A correct 40:1 mix gives the engine the lubrication it needs without over-oiling. Too little oil can score the cylinder and damage the piston; too much oil can foul the spark plug and cause heavy smoke.

Last updated: February 2026