Briggs & Stratton — Cylinder Balance Test
Testing & diagnosis · Engine
From a Briggs & Stratton service manual — check it applies to your exact model before use.
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Procedure
- With engine running at top no load speed, note spark at two ignition testers.
- If spark is equal at both testers, problem is not ignition related.
- Note RPM; ground out one cylinder with insulated screwdriver and note RPM loss.
- Allow engine to clear, then ground the other spark plug and note RPM loss.
- If difference between cylinders is less than 75 RPM, cylinders are considered equal.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 75 RPM difference threshold
Source: Briggs & Stratton service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.