Specifications

2LOCKED FOR PRINTING – SELECT SECT. NEEDED >

Fig. 6

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4. Ground the other spark plug and again note the

RPM loss.

If the difference between the two cylinders does not

exceed 75 RPM, the amount of work the two

cylinders are doing is considered equal.

An RPM loss greater than 75 RPM indicates that the

cylinder with the lower RPM loss is the weaker of the

two cylinders. Look to that cylinder for a problem.

See example below.

Engine RPM – Both Cylinders = 3400 RPM

Engine RPM – Cylinder #1 Grounded = 3300 RPM

Engine RPM – Cylinder #2 Grounded = 3100 RPM

Conclusion: Cylinder #1 is weaker cylinder.

NOTE: A partially sheared flywheel key will affect

ignition timing and engine performance.

Problems Affecting One Cylinder

NOTE: A two cylinder engine will run on one

cylinder as long as the power required for

the application does not exceed the power

produced by one cylinder.

1. Spark plug – A fouled spark plug may also

indicate that carburetor is out of adjustment.

2. Spark plug wire

3. Head gasket

4. Intake manifold – A leak at either end of the

intake manifold will affect only one cylinder.

5. Valves

6. Rings

7. Piston

8. Cylinder

Problems Affecting Two Cylinders

1. Carburetion

2. Crankcase vacuum

3. Ignition timing

For Briggs & Stratton Discount Parts Call 606-678-9623 or 606-561-4983