Craftsman 316794490 gas trimmer Parts

To replace the trimming line on your Craftsman gas trimmer model 316794490, you load a single 20 ft (6 m) length of the correct trimmer line through the cutting head eyelets, center it evenly, then wind it by turning the bump knob clockwise until about 5 inches of line remains on each side. For exact line type and diagrams, use the 316794490 owner's manual.

Quick steps to reload the bump head

• Stop the engine and let the cutting head come to a complete stop.
• Remove any old line and debris from the head.
• Cut one 20 ft (6 m) piece of new trimming line.
• Turn the bump knob clockwise to align the arrows on the head.
• Feed the line into the entry eyelet and out the exit eyelet.
• Pull until you have about 10 ft on each side (equal lengths).
• Turn the bump knob clockwise to wind the line until about 5 in (12.7 cm) protrudes from each side.

If you need to clear jammed line first

1. Firmly press in the tabs on the cutting head.
2. Remove the spool cover.
3. Remove welded line, tangles, or grass binding the reel.
4. Clean the inner reel, outer spool, and cover; then snap the cover back on.

Common line-feed problems and what to check

Symptom	Most common cause	What we do next
Line will not advance when bumping	Not enough line extended	Stop unit, push bump knob, pull line until about 4 in is outside head
Engine stalls when bumping	Bumping in tall grass	Tap bump knob on bare ground or hard soil at high speed
Line keeps sticking	Welded line or dirty head	Open head, remove welded section, clean and dry the head

Why it matters

Correct line length and even winding prevent binding, overheating, and poor bump-feed performance. Keeping the head clean also helps the line release smoothly and reduces stalling.

Last updated: February 2026

On the Craftsman 316794490 gas trimmer, the operator’s manual focuses on fuel type and maintenance, not a specific fuel hose inside diameter or outside diameter. For the correct replacement, we match the old hose by measuring ID and OD and confirming the routing shown in the 316794490 owner's manual.

How we identify the correct fuel line size

Fuel line is sized by inside diameter (ID) for fuel flow and outside diameter (OD) for sealing through the tank grommet and fittings.

• Drain the fuel tank into an approved container
• Pull the in-tank fuel filter and hose ends out with a small hook tool
• Measure the old hose ID and OD with calipers (or a drill-bit gauge)
• Compare the hose fit through the tank grommet; it must seal tightly
• Replace any hardened, cracked, or swollen hose sections

Typical sizes you will see on small gas trimmers

Many Craftsman and MTD-built trimmers use two different hose sizes (supply and return/primer). Use this as a starting point, then match what you measure.

Line (typical)	Purpose	Common ID range
Supply line	Tank to carburetor/primer feed	1/8 in. to 3/16 in.
Return line	Primer return back to tank	3/32 in. to 1/8 in.

Why it matters

A hose with the wrong ID can restrict fuel flow and cause hard starting or stalling. A hose with the wrong OD will not seal at the tank grommet, which pulls air into the fuel system and makes the engine run lean.

Last updated: February 2026

The Craftsman gas trimmer model 316794490 uses 0.095-inch (2.41 mm) diameter trimming line. This model is a bump-head style trimmer, so the correct line diameter helps it feed smoothly and cut consistently; see the 316794490 operator's manual for line and head details.

What to buy (and what to avoid)

Use round trimmer line in the correct diameter for the best balance of durability and feed performance.

• Line diameter: 0.095 in. (2.41 mm)
• Head type: bump head (tap to advance line)
• Best for: thicker grass and moderate weeds
• Avoid: undersized line (feeds poorly, breaks faster)
• Avoid: oversized line (can jam the head and overload the engine)

Quick compatibility guide

What you have	What it means	What to use
Bump head on 316794490	Line advances when you tap the head	0.095 in. line
Line keeps snapping	Often wrong diameter or old/brittle line	Fresh 0.095 in. line
Head jams or won’t feed	Often oversized line or incorrect winding	0.095 in. line, rewound evenly

Tips for loading line so it feeds correctly

• Cut two equal lengths (if your head uses two lines) and wind them evenly.
• Keep tension on the line while winding so it lays tight and flat.
• Do not cross-wrap; crossed coils cause binding.
• Replace line that looks chalky, flattened, or brittle.

Why it matters

Using the specified 0.095-inch line helps the bump head advance properly and prevents common issues like tangling, poor cutting, stalling, and premature wear on the cutting head and drive components.

Last updated: February 2026

On the Craftsman gas trimmer model 316794490, the model number is printed on the product identification label on the engine area (motor housing). We use that full model number to match the correct parts list, operator instructions, and maintenance specs in the 316794490 operator's manual.

Common places to check on a Craftsman Weedwacker

Look for a sticker or metal tag on the trimmer; it is usually on or near the engine.

• Side of the engine/motor housing (most common)
• Near the spark plug area or under/near the air filter cover
• Around the shaft housing close to the coupler
• Underside of the engine housing (you may need to tilt the unit to see it)
• Near the fuel tank or fuel cap area

What to write down (so parts match)

Record the information exactly as shown on the label.

What to capture	Example for this unit	Why it matters
Model number	316794490	Ensures the correct Craftsman parts diagram and part fit
Dashes/periods	316.794490 (if shown)	Some labels include punctuation that helps identify the series
Serial/date code (if present)	Varies	Helps confirm production run when ordering certain assemblies

Why it matters

Craftsman trimmers often share similar housings, but parts like the carburetor, ignition coil, flexible drive shaft, and cutting head components can vary by model. Using the exact model number prevents ordering the wrong part and saves time during repair.

Last updated: February 2026

When your Craftsman gas line trimmer model 316794490 dies as you squeeze the throttle, the engine is usually running too rich or starving for air or fuel under load. The fastest fixes are servicing the air filter, checking the spark plug gap, and confirming fresh fuel and proper throttle operation per the 316794490 owner's manual.

Most common causes (and what to check first)

• Dirty air filter: A clogged filter restricts airflow and can make the engine bog and stall when you accelerate.
• Spark plug condition or gap: This model calls for a 0.025 in. (0.635 mm) gap; a fouled plug often shows up as stalling on throttle.
• Carburetor fuel delivery: Varnish from old fuel or a leaking gasket can cause a lean bog or rich stall.
• Throttle control not returning to idle smoothly: The manual notes the throttle should return automatically to idle.
• Incorrect trimming line: Using the wrong line type or diameter can overload the engine; the manual specifies 0.095 in. line.

Step-by-step troubleshooting (safe, quick checks)

1. Inspect the air filter and clean or replace it if it is dirty. If you need a replacement, use the exact engine air filter 753-05254.
2. Check the spark plug: remove it, inspect for heavy carbon or wet fuel, and set the gap to 0.025 in. If replacement is needed, use the exact spark plug 794-00082.
3. Confirm fresh fuel: drain old fuel and refill with fresh, properly mixed fuel (if applicable to your engine setup) in an approved container.
4. Verify throttle movement: squeeze and release the trigger; it must snap back to idle. Fix binding cables or a damaged housing.
5. If it still stalls, plan on carburetor service: a leaking gasket or dirty carb can cause stalling when you open the throttle.

Quick symptom guide

What it does when you give gas	Most likely issue	Best first action
Bogs, then dies	Air restriction or lean fuel delivery	Clean/replace air filter; check fuel freshness
Dies instantly	Ignition miss or severe fuel issue	Check spark plug and gap; inspect carb connections
Runs only with partial choke	Lean condition	Clean carb passages; check gaskets

Why it matters

Stalling on acceleration usually means the engine cannot maintain the correct air-fuel mix under load. Fixing it early prevents hard starting, overheating, and poor cutting performance.

Last updated: February 2026