Poulan BP406 User Manual - Page 8

REPLACE SPARK PLUG Replace spark plug each year to ensure the engine starts easier and runs better. Set spark plug gap at 0.034 inch (0.85 mm). Ignition timing is fixed, nonadjustable. 1. Twist, then pull off spark plug boot. 2. Remove spark plug from cylinder and discard. 3. Replace with NGK BPMR71-9 spark plug and tighten securely with a 3/4 inch (19 mm) socket wrench. 4. Reinstall the spark plug boot. CARBURETOR ADJUSTMENTS Your carburetor is equipped with limiter caps. Carburetor adjustment is a complicated task. We recommend that you take your unit to an authorized service dealer. Damage may occur if you turn the needles beyond the limiter stops. TROUBLESHOOTING TABLE WARNING: Always stop unit and disconnect spark plug before performing any of the recommended remedies below other than remedies that require operation of the unit. TROUBLE Engine will not start. Engine will not idle properly. Engine will not accelerate, lacks power, or dies under a load. CAUSE 1. Engine flooded. 2. Fuel tank empty. 3. Spark plug not firing. 4. Fuel not reaching carburetor. 5. Compression low. 1. Fuel not reaching carburetor. 2. Carburetor requires adjustment. 3. Crankshaft seals worn. 4. Compression low. 1. Air filter dirty. 2. Fuel not reaching carburetor. 3. Spark plug fouled. 4. Carburetor requires adjustment. 5. Carbon build up. 6. Compression low. REMEDY 1. See "Starting a Flooded Engine" in Operation section. 2. Fill tank with correct fuel mixture. 3. Install new spark plug. 4. Check for dirty fuel filter; replace. Check for kinked or split fuel line; repair or replace. 5. Contact an authorized service dealer. 1. Check for dirty fuel filter; replace. Check for kinked or split fuel line; repair or replace. 2. See "Carburetor Adjustment" in Service and Adjustments section. 3. Contact an authorized service dealer 4. Contact an authorized service dealer. 1. Clean or replace air filter. 2. Check for dirty fuel filter; replace. Check for kinked or split fuel line; repair or replace. 3. Clean or replace spark plug and re-gap. 4. See "Carburetor Adjustment" in Service and Adjustments section. 5. Contact an authorized service dealer. 6. Contact an authorized service dealer. Engine smokes excessively. 1. Choke partially on. 2. Fuel mixture incorrect. 3. Air filter dirty. 4. Carburetor requires adjustment. 1. Adjust choke. 2. Empty fuel tank and refill with correct fuel mixture. 3. Clean or replace air filter. 4. See "Carburetor Adjustment" in Service and Adjustments section. Engine runs hot. 1. Fuel mixture incorrect. 2. Spark plug incorrect. 3. Carburetor requires adjustment. 4. Carbon build up. 1. See "Fueling Engine" in Operation section. 2. Replace with correct spark plug. 3. See "Carburetor Adjustment" in Service and Adjustments section. 4. Contact an authorized service dealer. -- 8 --