Common Issues
Tools Needed:
- Socket set
- Screwdrivers (flat and Phillips)
- Spark plug wrench
- Multimeter
- Air compressor
- Safety gloves
Quick Troubleshooting Steps
- Safety First: Disconnect spark plug wire on gas models or battery on electric models before any repairs.
- Check Fuel System: Ensure fresh gasoline (less than 30 days old) and clean fuel filter.
- Inspect Air Filter: Clean or replace clogged air filters that restrict airflow.
- Examine Spark Plug: Check for fouling, corrosion, or improper gap (typically 0.030 inches).
- Test Battery: Check voltage (should be 12.6V+ for 12V systems) and clean terminals.
- Blade Inspection: Ensure blades are sharp, balanced, and undamaged.
- Deck Cleaning: Remove grass buildup from under the deck for proper airflow.
Engine Problems
| Engine Types | Briggs & Stratton, Kohler, Craftsman |
| Fuel Type | Regular Unleaded (87 Octane) |
| Oil Type | SAE 30 (Summer), 10W-30 (Multi-season) |
| Oil Capacity | 20-24 oz (varies by model) |
| Spark Plug Gap | 0.028 - 0.031 inches |
| Engine HP Range | 5.5 - 7.25 HP (Push), 18-24 HP (Riding) |
Engine Won't Start
- No Fuel: Check fuel level, fuel shutoff valve, and fuel lines
- Bad Spark Plug: Test spark, replace if no spark visible
- Clogged Carburetor: Clean jets and float bowl
- Old Gasoline: Drain and replace with fresh fuel
- Safety Switch: Check seat, brake, and blade engagement switches
Engine Runs Poorly
- Rough Idle: Adjust carburetor idle screw
- Loss of Power: Check air filter, fuel filter, and exhaust
- Overheating: Clean cooling fins and check oil level
- Excessive Smoke: Blue smoke indicates oil burning, white smoke suggests coolant leak
Electrical Issues
Battery Problems
Most Craftsman riding mowers use 12V batteries. Check voltage (12.6V+ when charged), clean corroded terminals, and ensure proper charging system operation.
Starting System
Test starter solenoid, starter motor, and ignition switch. Listen for clicking sound when turning key - indicates solenoid engagement but possible starter failure.
Charging System
Check alternator/stator output (typically 13.5-14.5V when running). Low output indicates faulty voltage regulator or alternator.
Safety Switches
Craftsman mowers have multiple safety switches (seat, brake, blade, clutch). Bypass each temporarily to identify faulty switches preventing startup.
Wiring Issues
Check for corroded connectors, frayed wires, and loose grounds. Pay special attention to wiring near vibration points and moving parts.
Electric Start Models
For push mowers with electric start, check wall outlet, extension cord, and starter motor. Ensure battery pack is fully charged for cordless models.
Electrical Testing Procedures
Battery Test
Load test battery - should maintain 9.6V+ under load for 15 seconds
Starter Test
Bench test starter - should draw 75-150 amps with no load
Alternator Test
Measure AC output at stator wires, then DC output at battery while running
Switch Test
Continuity test all safety switches in both engaged and disengaged positions
Wiring Test
Voltage drop test - no more than 0.5V drop across any circuit
Fuse Check
Locate and test all fuses (typically 5A, 10A, 20A, 30A depending on circuit)
Cutting Problems
| Problem | Possible Cause | Solution |
|---|---|---|
| Uneven cutting | Uneven tire pressure, worn blades, deck not level | Check tire pressure (12-14 PSI), sharpen/replace blades, level deck |
| Grass not discharging | Wet grass, clogged deck, dull blades, high grass | Mow when dry, clean deck, sharpen blades, cut more frequently |
| Scalping (cutting too low) | Deck too low, uneven terrain, worn rollers | Raise cutting height, avoid uneven areas, replace rollers |
| Vibration during operation | Unbalanced blade, bent blade, loose components | Balance or replace blade, tighten all bolts and pulleys |
| Blade won't engage | Faulty PTO switch, broken belt, bad clutch | Test PTO switch, inspect belt, check electric clutch |
| Poor bagging performance | Full bag, clogged chute, wrong blade type | Empty bag frequently, clean chute, use high-lift blade |
Deck Adjustment Specifications
- Cutting Height Range: 1.5" - 4.5" (varies by model)
- Deck Level Tolerance: ±0.125" front to back, ±0.25" side to side
- Blade Tip Speed: 18,000-19,000 FPM for optimal cutting
- Deck Belt Tension: 1/2" deflection at midpoint
- Spindle Play: Less than 1/16" vertical movement
- Anti-scalp Roller Clearance: 1/2" above ground at highest setting
Manual Downloads
Popular Craftsman Models
CMXGRAM113004
21" Self-Propelled Gas Mower
CMEMW213
21" Electric Walk Behind
CMXGVBAG02833
28" Rear Engine Rider
CMXGZAMC75604
46" Zero Turn Mower
Engine Specific Manuals
Briggs 550EX
5.5 HP Engine Manual
Briggs 675EX
6.75 HP Engine Manual
Kohler CV740
24 HP Engine Manual
Craftsman 190cc
7.25 HP Engine Manual