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Home›Repair guides›Generac›Cylinder Balance Test

Generac GN-724 / GN724 — Cylinder Balance Test

Testing & diagnosis · Engine

For the Generac GN-724 / GN724, from the Generac service manual.

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Procedure

  1. Run engine at top no load speed.
  2. Attach ignition tester between spark plug lead and each spark plug.
  3. Ground one cylinder with insulated screwdriver; note RPM loss.
  4. Ground other cylinder; note RPM loss.
  5. If difference exceeds 75 RPM, cylinder with least RPM loss is weakest.

Tools required

  • Two ignition testers (Generac P/N 0C5969) Amazon
  • Insulated screwdriver Amazon

Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.

Specs & values

  • RPM difference should not exceed 75 RPM

Source: Generac 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.

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