Craftsman 636796241 51.7-cc gas brushwacker Parts

Landscapers sometimes remove the debris guard on a string trimmer to cut faster and see the cutting path better, especially when edging. On a Craftsman 636796241 51.7-cc gas brushwacker, taking the guard off also increases the amount of thrown debris and the chance of injury, so we recommend keeping the guard installed.

What they’re trying to gain (and what they give up)

Removing the guard is usually about speed and access, not better trimming quality.

Common reasons pros remove the guard

• More visibility for precise edging along sidewalks and curbs
• Easier reach into tight spots (fences, shrubs, landscape borders)
• Less drag and fewer hang-ups in heavy weeds
• Slight weight reduction at the cutting end
• Fewer interruptions when working quickly around obstacles

Tradeoffs that matter

• More rocks, sticks, and wire get thrown farther and faster
• Higher risk of cuts, eye injuries, and leg impacts
• More chance of damaging siding, windows, vehicles, and irrigation heads
• More line breakage and faster line consumption in rough areas
• Less protection if the trimmer head contacts hard surfaces

Safety guidance we use for this model

For the Craftsman 636796241, the guard is part of the safety system that helps control debris and defines a safer cutting zone.

Minimum PPE if you’re trimming (guard on)

• Safety glasses plus a face shield
• Long pants and closed-toe boots
• Hearing protection (gas brushwacker engines are loud)
• Gloves with good grip

If the guard is missing or damaged

Use the trimmer only after restoring the guard; this is the fastest way to get back to safe, consistent operation. Use Sears PartsDirect to search the model number and match the correct guard and mounting hardware.

Quick comparison

Setup	Speed	Visibility	Debris control	Injury risk
Guard installed	Medium	Medium	High	Lower
Guard removed	Higher	Higher	Low	Higher

Why it matters

A 51.7-cc gas brushwacker has enough power to launch debris with real force. The guard reduces thrown objects and helps keep the cutting area predictable, which protects you, bystanders, and property.

Last updated: February 2026

For a Craftsman 636796241 51.7-cc gas brushwacker, .095 trimmer line is the better default choice because it holds up longer in thick grass and weeds. Use .080 line when you want easier feeding and lighter cutting for routine edging.

Quick pick guide

• Choose .095 for heavy weeds, fence lines, and rocky edges (better durability)
• Choose .080 for light trimming and clean edging (easier to spin and feed)
• If your head accepts both sizes, start with .095 and drop to .080 if the engine bogs down
• Match line size to the trimmer head rating and spool capacity
• Replace line when it gets brittle, flattened, or keeps breaking short

.080 vs .095: what changes

Feature	.080 line	.095 line
Best for	Light grass, edging	Thick grass, weeds, brushy areas
Durability	Good	Better
Cutting load on engine	Lower	Higher
Line feed	Typically easier	Can be slightly harder
Typical use case	Residential touch-ups	Heavy-duty trimming

How to choose the right line for your trimmer head

1. Check the trimmer head markings (often molded into the head) for the maximum line diameter.
2. If the head is rated for .095, use it for most work on this gas model.
3. If you mainly edge sidewalks and trim light grass, .080 reduces drag and can feel smoother.

Why it matters

Line diameter affects cutting performance and how hard the engine has to work. Too-thick line can reduce RPM and increase fuel use; too-thin line can snap constantly and slow the job.

For help confirming you have the correct model number before choosing parts or accessories, use how to find your appliance model number (and what it means for parts).

Last updated: February 2026

Yes, you can often run .095-inch trimmer line in a trimmer that normally uses .080-inch line, but on a Craftsman 636796241 (51.7-cc gas brushwacker) it can increase drag, reduce RPM, and make the head feed less reliably. Use it only if the trimmer head and eyelets physically accept the thicker line.

Quick fit check (before you spool it)

• Confirm the trimmer head’s maximum line diameter; many heads are designed for a specific range.
• Make sure .095 line slides freely through the eyelets; binding causes poor bump-feed and rapid wear.
• Check spool capacity; thicker line means less length on the spool.
• Spin the head by hand (engine off) to ensure nothing rubs.
• If the head is a fixed-line or blade-capable setup, verify you are using the correct head style for line.

What changes when you go thicker

Item	.080 line (typical)	.095 line (typical)
Cutting load on engine	Lower	Higher
Best use	Grass, light weeds	Heavier weeds, thicker stems
Runtime/fuel use	More efficient	Uses more fuel under load
Feed behavior	Usually smoother	More likely to stick if head is tight

How to try .095 without causing problems

• Start with a shorter cut length (keep the line trimmed to the guard knife).
• Avoid full-throttle “bogging”; let the engine stay in its power band.
• If bump-feed becomes inconsistent, switch back to .080 or use a premium .080 line.
• Replace worn eyelets; sharp edges can grab thicker line.

Why it matters

Line diameter directly affects cutting resistance. If the head is not designed for .095, the extra drag can make the trimmer feel weak, overheat the clutch area, and cause frequent feed issues.

For model identification and parts lookup tips, use how to find your appliance model number (and what it means for parts).

Last updated: February 2026

To replace the trimmer head on your Craftsman model 636796241 (51.7-cc gas brushwacker), you typically lock the shaft, then unthread the head from the gearbox. Many heads use reverse (left-hand) threads, so the loosening direction can be opposite of what you expect.

Before you start (safety and setup)

• Shut the engine off and let it cool completely.
• Disconnect the spark plug wire so the trimmer cannot start.
• Wear gloves; the cutting attachment area can be sharp.
• Clean grass and debris off the head and gearbox so you can see the fasteners.
• Set the trimmer on a stable surface.

Steps to remove and install the head

1. Lock the shaft/gearbox: Look for a small hole in the gearbox housing or head area. Insert a screwdriver, nail, or the locking pin (if your unit has one) and rotate the head until the shaft locks.
2. Unthread the head: With the shaft locked, turn the head to loosen it. If it will not loosen, try the opposite direction because many brushcutter-style heads use left-hand threads.
3. Remove any adapters or washers: Note the order of spacers, cupped washers, or adapters so you can reinstall them the same way.
4. Install the new head: Thread it on by hand first to avoid cross-threading, then snug it while the shaft is locked.
5. Test for secure fit: Spin the head by hand to confirm it runs true and does not wobble.

Quick direction check (common setups)

What you see	What it usually means	What to try
Head will not loosen turning left	Possible left-hand thread	Try loosening by turning right
Shaft-lock hole present	Designed for a locking pin/tool	Lock shaft before loosening/tightening
Wobble after install	Washer/spacer order wrong or cross-threaded	Recheck hardware order; reinstall by hand-starting threads

Why it matters

A correctly installed trimmer head prevents vibration, protects the gearbox, and helps the line feed properly. Cross-threading or missing spacers can strip threads and cause the head to come loose during use.

Helpful related reading

• Use our guide to confirm you are matching the correct model and parts list: how to find your appliance model number (and what it means for parts)

Last updated: February 2026