CONTENTS
SOUNDS
EXTERNAL

UNEVEN EXHAUST SOUND AT TAILPIPE

CONDITION(S)

• NO EVEN HUMMING OF EXHAUST GAS
• NOISE IS RHYTHMIC SOUND OF "ROOOOM"; EXHAUST MAY SOUND OUT-OF-TUNE

POTENTIAL CAUSE(S)

CHECK THESE FIRST:

1. WORN SPARK PLUG(S)
Replace spark plugs.

2. FAULTY DISTRIBUTOR CAP OR ROTOR
Replace distributor cap or rotor.

3. SHORTED, DAMAGED, DISCONNECTED OR MISROUTED SPARK PLUG WIRES
Connect or replace spark plug wires.

CHECK THESE NEXT:

4. UNBALANCED CARBURETOR FUEL/AIR MIXTURE
Have carburetor fuel/air mixture professionally balanced.

5. WORN PISTON RINGS OR CYLINDERS
Use slightly heavier grade oil.
If sound does not improve, have components professionally serviced.

CHECK THESE LAST:

6. MALADJUSTED BREAKER POINTS
Have breaker points professionally adjusted.

7. WEAK BREAKER POINT SPRING
Have breaker point spring professionally replaced.

CONTENTS
CHIRPING SOUND UNDERNEATH CAR
GRINDING SOUND