Craftsman 316794371 line trimmer Parts

For the Craftsman 316794371 2-cycle 25cc trimmer, we use fresh unleaded gasoline mixed with 2-cycle oil at a 40:1 ratio (3.2 fl oz oil per 1 U.S. gallon of gas). Mix in a separate fuel can, not in the fuel tank; follow the 316794371 operator’s manual for fuel handling and safety steps.

Fuel and oil you should use

• Gas: fresh unleaded gasoline (use fuel less than 30 days old)
• Oil: 2-cycle oil designed for air-cooled engines
• Mix ratio: 40:1 (gasoline:oil)
• Do not use: E85 fuel

Mixing chart (40:1)

Gas amount	2-cycle oil amount	Notes
1 U.S. gallon (3.8 L)	3.2 fl oz (95 ml)	Pour oil into gas can, then mix thoroughly
1 liter	25 ml	Same 40:1 ratio

Best practices to prevent hard starting and rough running

• Shake or swirl the fuel can before each refill to re-mix oil and gas.
• If you use alcohol-blended fuel, keep it fresh and consider a stabilizer in the fuel can.
• Store fuel in an approved container; keep the cap tight to reduce moisture absorption.
• If the trimmer has been sitting, drain old fuel and refill with a fresh 40:1 mix.
• Keep the air intake clean; a clogged filter can make the engine run rich and bog down.

Why it matters

A correct 40:1 mix lubricates the 2-cycle engine properly. Too little oil can score the cylinder and piston; too much oil can foul the spark plug, smoke excessively, and cause poor throttle response.

Last updated: January 2026

To replace the trimming line on your Craftsman line trimmer model 316794371, remove the bump knob, lift out the inner reel and spring, wind the correct trimmer line in the direction shown on the reel, then reinstall the reel and bump knob. Use the steps in the 316794371 owner's manual.

Before you start (safety and setup)

• Shut the engine off and let the muffler and cutting head cool.
• Disconnect the spark plug boot so the trimmer cannot start accidentally.
• Wear gloves and eye protection.
• Clean grass and debris off the cutting head so parts seat correctly.
• Use only the line type and diameter listed in the specifications for this model (metal-reinforced line, wire, chain, or rope is unsafe).

Replace the line (bump head inner reel method)

Part 1: Remove the inner reel

• Hold the outer spool with one hand.
• Unscrew the bump knob counterclockwise.
• Pull the inner reel out of the outer spool.
• Remove the spring from the inner reel.
• Clean the inner reel, spring, shaft, and inside of the outer spool; check indexing teeth and holding slots for wear.

Part 2: Wind new line onto the inner reel

Use the winding direction shown on the bottom of the inner reel.

• Standard line method: Fold the line in half to make a loop, seat the loop in the split-wall slot, wind tightly, and leave about 6 inches of line at the end.
• Split line method: Cut one 6-foot length, split each end about 6 inches, feed into the top and bottom holes, wind tightly until divided, and leave about 6 inches.
• Lock the two ends into the .095 holding slots so the line does not unwind.

Part 3: Reinstall the reel

• Reinstall the spring.
• Set the inner reel back into the outer spool.
• Thread the line ends out correctly and reinstall the bump knob.

Quick reference table

Step	What you do	What to watch for
Remove	Unscrew bump knob, lift reel and spring	Keep spring in place for reassembly
Wind	Wind tightly in the indicated direction	No overlapping; prevents tangles
Install	Refit reel, reinstall bump knob	Leave about 6 inches per side

Why it matters

Correct line length and winding direction help the bump feed work properly, reduce tangles, and let the shield blade trim excess line to the right cutting length.

Last updated: January 2026

To start your Craftsman line trimmer model 316794371, set the unit on stable ground with the cutting head clear of anything, then pull the starter rope in a steady motion until the engine starts. Follow the exact starting and stopping steps in the 316794371 owner's manual.

Before you pull the starter rope (safety and setup)

• Wear eye protection, heavy long pants, boots, gloves, and a long-sleeve shirt.
• Keep the cutting head shield installed; never run without the proper trimming line installed.
• Make sure the cutting head is not touching grass, dirt, or any object.
• Hold the trimmer firmly with both hands and keep stable footing.
• Stay in the correct starting position to avoid accidental starting.

Basic starting checklist (what we do every time)

1. Place the trimmer on level ground.
2. Confirm the cutting head is clear and the shield is in place.
3. Grip the unit securely and pull the starter rope handle until the engine fires and runs.

If it will not start or starts then dies

Common causes on gas trimmers include stale fuel, restricted airflow, or fuel delivery issues.

Symptom	Most common cause	What to check first
No start	Fuel or spark issue	Fresh fuel mix, spark plug condition/gap
Starts then stalls	Dirty air filter or carburetor issue	Air filter, carburetor mounting gasket
Runs rough	Fuel restriction or carburetor tuning	Air filter, fuel lines, carburetor

Parts that often matter for hard-starting

• Mtd line trimmer air filter 753-06417 (clean and re-oil regularly)
• Mtd line trimmer carburetor 753-06190 (fuel metering and starting)

Why it matters

Starting with the cutting head clear and the shield installed helps prevent sudden line rotation contact and reduces the chance of stalling during startup. A clean air filter and good fuel delivery also make cold starts faster and more consistent.

Last updated: January 2026