Craftsman 917773743 gas line trimmer Parts

For the Craftsman 917773743 gas line trimmer, we use fresh unleaded gasoline mixed with 2-cycle (two-stroke) engine oil at a 40:1 ratio (that is 2.5% oil). This correct fuel mix protects the engine from scoring, overheating, and hard starting.

Fuel and oil mix you should use

• Gas: fresh, clean unleaded gasoline
• Oil: 2-cycle engine oil (air-cooled small engine oil)
• Mix ratio: 40 parts gas to 1 part oil
• Mix strength: 2.5% oil
• Mix only what you will use soon; old fuel causes starting and running problems

Quick mix chart (40:1)

Gasoline amount	2-cycle oil to add
1 gallon	3.2 fl oz
1/2 gallon	1.6 fl oz
1 quart	0.8 fl oz

How we recommend mixing fuel (best practice)

• Use an approved fuel can; add about half the gas first
• Measure the oil accurately; pour it into the can
• Add the remaining gas, then cap and shake to blend
• Fill the trimmer outdoors with the engine off and cool
• Wipe up spills before starting

Common symptoms of the wrong mix

What you notice	Most common cause
Engine revs but lacks power	mix too lean (not enough oil) or stale fuel
Excessive smoke, oily muffler	mix too rich (too much oil)
Hard starting, surging	old fuel, water in fuel, dirty carburetor

Why it matters

A 2-cycle engine depends on oil in the fuel for lubrication. Using straight gas or the wrong ratio can quickly damage internal parts and shorten engine life.

For model-specific fuel notes and safety warnings, follow the 917773743 owner's manual.

Last updated: February 2026

When your Craftsman gas line trimmer model 917773743 dies as you squeeze the throttle, the engine is usually running too rich or too lean under load. The most common causes are restricted airflow (dirty air filter), stale fuel, or a carburetor that needs cleaning and adjustment; start with the quick checks in the 917773743 owner's manual.

Quick checks that fix most “dies when I give it gas” problems

• Replace or clean the air filter; a clogged filter chokes airflow and the engine bogs or stalls.
• Drain old fuel and refill with fresh, properly mixed fuel (if 2-cycle) or fresh gasoline (if 4-cycle).
• Inspect the fuel cap vent; a plugged vent can starve fuel and cause stalling when you accelerate.
• Check the spark plug condition and gap; a fouled plug misfires more under throttle.
• Look for cracked or loose fuel lines and a dirty in-tank fuel filter.
• Verify the throttle linkage moves smoothly and returns fully.

Carburetor and fuel delivery: what to do next

If the trimmer idles but dies on acceleration, the carburetor’s low-speed circuit is often restricted.

1. Remove the air filter and housing; clean any heavy debris.
2. If it runs better briefly with the filter off, replace the filter and recheck.
3. If it still stalls, clean the carburetor and jets, then set mixture screws to the baseline listed in the 917773743 owner's manual.

Symptoms guide

What it does	Most likely cause	Best first step
Idles, then dies when throttled	Dirty carburetor low-speed circuit	Clean carburetor, set baseline mixture
Bogs and blows black smoke	Too rich (air filter clogged)	Replace/clean air filter
Surges, then stalls	Fuel restriction or air leak	Check fuel cap vent, lines, filter

Why it matters

Stalling on throttle is a sign the engine cannot maintain the correct air-fuel mix as RPM rises. Fixing airflow and fuel delivery prevents hard starting, plug fouling, and poor cutting power.

Last updated: February 2026

To replace the trimmer line on your Craftsman 917773743 gas line trimmer, we reload the cutting head with the correct diameter line, wind it evenly, then feed the ends through the eyelets so the head can bump-feed smoothly. Use the steps in the 917773743 owner's manual for your exact head style.

Quick steps to reload trimmer line

• Shut the engine off and let the muffler and cutting head cool completely.
• Disconnect the spark plug wire so the trimmer cannot start accidentally.
• Clean grass and debris off the head so the spool and arrows are easy to see.
• Open the head (cap or knob style varies) and remove any old line pieces.
• Cut two equal lengths of new line (most heads use two pieces).
• Wind the line in the direction shown on the spool (usually an arrow on the spool).
• Thread the line ends through the eyelets and reassemble the cap.

Getting the winding right (prevents jams)

Most line-feed problems come from uneven winding or crossing the line inside the spool.

What to do	What it prevents
Wind tight, even layers	Line tangles and “welds” together
Match the arrow direction	Line won’t feed when you bump
Leave equal tails out of both eyelets	Vibration and poor cutting
Do not overfill the spool	Head binds and line breaks

Before you start: choose the right line

Use a quality round or twisted trimmer line and match the diameter your head is designed for.

• If the line is too thick, it will not feed.
• If the line is too thin, it breaks quickly.
• If the line is brittle, replace it (old line snaps and causes constant reloading).

Why it matters

Correctly loaded line keeps the bump-feed working, reduces vibration, and helps the Craftsman 917773743 cut cleanly without stalling or shredding the line.

Last updated: February 2026

For Craftsman gas line trimmer model 917773743, the fuel line size is matched by inside diameter (ID) and outside diameter (OD) so it seals on the tank grommet, primer bulb, and carburetor fittings. Most small-engine trimmers use two different line sizes; confirm the exact routing and line callouts in the 917773743 owner's manual.

Typical fuel line sizes used on small gas trimmers

These are the most common sizes you will see when replacing trimmer fuel tubing; use them as a starting point, then match to your original line and fittings.

Line function	Common OD	Common ID
Small return/primer line	9/64 in	0.080 in
Main supply line (tank to carb)	3/16 in	0.090 to 0.125 in

How we recommend sizing the replacement line

• Measure the ID of the old line (or the fitting barb) with a caliper.
• Check the OD where the line passes through the fuel tank grommet.
• Replace both lines if one is brittle; old tubing hardens at the same rate.
• Cut the ends square; angled cuts can cause air leaks.
• Route the lines exactly like the diagram so the filter stays on the tank bottom.

Why it matters

A fuel line that is slightly loose pulls air and causes hard starting, surging, or stalling. A line that is too tight kinks or restricts fuel flow, which can mimic carburetor problems.

When to replace other parts at the same time

If you are already servicing the trimmer, inspect wear items that affect performance:

• Line trimmer throttle cable assembly 586861201 if throttle response is inconsistent
• High-wheel trimmer spindle assembly 596878501 if the cutting head wobbles or binds
• Line trimmer belt 532185476 if drive or head speed drops under load

Last updated: February 2026