Fix Craftsman Lawn Mower

Craftsman mowers are basically rebadged Briggs engines on MTD frames - same parts as half the mowers at Home Depot. That’s actually good news because parts are cheap and everywhere. Here’s how to fix the usual problems.

Table of Contents

• Won’t Start Problems
• Self-Propel Issues
• Carburetor Problems
• Cutting Problems
• Parts and Costs

Won’t Start Problems

Step-by-Step Diagnosis

1. Check fuel - Is it fresh? Gas over 30 days old causes problems
2. Prime the engine - Push primer 3-5 times
3. Check spark plug - Remove and inspect
4. Check air filter - Dirty filter restricts airflow
5. Test for spark - Ground plug and pull cord

[NEED IMAGE: Craftsman won’t start diagnosis]

Fuel System Fixes

Old fuel symptoms:

• Hard starting
• Rough running
• Dies under load

Fix:

1. Drain fuel tank completely
2. Remove and drain carburetor bowl
3. Add fresh fuel with stabilizer
4. Try starting

Spark Plug Issues

Bad plug symptoms:

• No start
• Misfiring
• Hard starting

Craftsman plug specs:

• Most models: RC12YC or equivalent
• Gap: 0.030 inches

Self-Propel Issues

Drive Cable Adjustment

The drive cable is the #1 cause of self-propel problems.

Symptoms:

• Weak propulsion
• No engagement
• Intermittent operation

Adjustment:

1. Locate cable at transmission (rear)
2. Find adjustment barrel
3. Turn to increase tension
4. Test engagement
5. Repeat until smooth

[NEED IMAGE: Craftsman drive cable adjustment location]

Drive Belt Replacement

Symptoms of worn belt:

• Slipping under load
• Squealing noise
• Complete failure to propel

Replacement:

1. Tip mower back (air filter up)
2. Remove blade for access
3. Locate drive belt
4. Release tensioner
5. Remove old belt
6. Install new belt
7. Verify routing

Transmission Failure

Symptoms:

• Cable adjusted but still no propel
• Grinding noise from rear
• Wheels spin freely

Fix: Replace transmission. Not rebuildable on most Craftsman models.

Cost: $60-100 for transmission

Carburetor Problems

Cleaning vs Replacement

When to clean:

• Hard starting (not no-start)
• Runs rough
• Surges at idle

When to replace:

• Multiple cleaning attempts failed
• Visible damage
• Internal parts worn

Carburetor Cleaning

Most Craftsman mowers use Briggs carburetors.

Steps:

1. Remove air filter housing
2. Disconnect fuel line
3. Remove carburetor (2 bolts)
4. Remove float bowl
5. Spray all passages with carb cleaner
6. Clear jets with thin wire
7. Reassemble with new gasket
8. Reinstall

[NEED IMAGE: Craftsman carburetor cleaning steps]

Common Carburetor Parts

Part	Part Number
Carburetor	799866 (Briggs)
Gasket set	795629
Float needle	694920
Primer bulb	694394

Cutting Problems

Uneven Cut

Causes:

• Dull blade
• Bent blade
• Deck not level
• Wheel height mismatch

Fix:

1. Check blade condition
2. Sharpen or replace
3. Level deck side-to-side
4. Match all wheel heights

Grass Not Discharging

Causes:

• Buildup under deck
• Dull blade
• Wet grass
• Engine RPM low

Fix:

1. Clean deck thoroughly
2. Sharpen blade
3. Mow when dry
4. Check throttle position

Vibration

Causes:

• Bent blade
• Loose blade bolt
• Damaged crankshaft
• Worn engine mounts

Fix:

1. Remove and inspect blade
2. Check blade bolt torque
3. If still vibrating, check crankshaft

Parts and Costs

Common Repair Costs

Repair	DIY Cost	Shop Cost
Spark plug	$5-8	$25-40
Air filter	$8-15	$25-40
Carburetor clean	$10-20	$75-125
Carburetor replace	$25-40	$100-150
Drive cable	$15-25	$50-80
Transmission	$60-100	$150-200
Blade	$20-35	$40-60

When to Repair vs Replace

Repair if:

• Mower is less than 5 years old
• Single issue (not multiple problems)
• Repair cost under 50% of new mower

Replace if:

• Multiple major issues
• Repair cost exceeds 50% of new
• Mower is 8+ years old with problems

Maintenance Schedule

Every Use

• Check oil level
• Clear debris from deck

Every 25 Hours

• Change oil
• Clean air filter
• Check blade

Every Season

• Replace spark plug
• Replace air filter
• Sharpen blade
• Clean carburetor

Related Guides

• Craftsman Lawn Mower Parts Diagram
• Craftsman Carburetor Repair
• Lawn Mower Won’t Start
• Self-Propelled Mower Repair

Summary

Most Craftsman problems are fuel or carburetor related. Start with fresh fuel and basic maintenance. Self-propel issues usually need cable adjustment. The carburetor is the most common part needing service on older Craftsman mowers.