Poulan Pro BP406 - Manual (Page 8)

-- 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). Igni-
tion timing is fixed, nonadjustable.
1. Twist, then pull off spark plug boot.
2. Remove spark plug from cylinder and dis-
card.
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.
TROUBLE CAUSE REMEDY
Engine will not
start.
1. Engine flooded.
2. Fuel tank empty.
3. Spark plug not firing.
4. Fuel not reaching
carburetor.
5. Compression low.
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.
Engine will not
idle properly.
1. Fuel not reaching
carburetor.
2. Carburetor requires
adjustment.
3. Crankshaft seals worn.
4. Compression low.
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. Air filter dirty.
2. Fuel not reaching
carburetor.
3. Spark plug fouled.
4. Carburetor requires
adjustment.
5. Carbon build up.
6. Compression low.
Engine will not
accelerate,
lacks power, or
dies under a
load.
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.
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.