Generac — Spark Test (Ignition System)
Testing & diagnosis
From a Generac service manual covering: GN-190, GN-220, NP-30G, NP-40G. Check it applies to your exact model before use.
Applies to: Generac NP-30G, Generac GN-190 / GN-220 engine, Generac GN-190 or GN-220 engine
Procedure
- Disconnect the high tension lead from the spark plug.
- Attach the spark plug high tension lead to the spark tester terminal.
- Connect the spark tester clamp to the engine cylinder head.
- Crank the engine rapidly; the engine must be turning at 350 rpm or more.
- If spark jumps the tester gap, the ignition system is operating satisfactorily.
Tools required
- spark tester Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Engine must turn at 350 rpm or more
Full service-parts list: Generac NP-30G →
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.