Generac — Test 25 – Testing Starter Motor Performance
Testing & diagnosis
From a Generac service manual covering: GP1800, GP1850, GP3250, GP5000, GP5500, GP6500, GP7000, GP8000. Check it applies to your exact model before use.
Applies to: Generac GP1800, Generac GP3250, Generac GP5000, Generac GP5500, Generac GP6500, Generac GP7000, Generac GP8000, Generac OHVI engine
Before you start
- DO NOT rotate engine with electric starter with spark plugs removed.
Procedure
- Remove starter motor and assemble to test bracket; clamp in vise.
- Connect a fully charged 12 volt battery and clamp-on ammeter.
- Activate the starter (jump terminal on Starter Contactor).
- Note reading on clamp-on ammeter and tachometer.
- Take readings after ammeter and tachometer stabilize (2-4 seconds).
Tools required
- clamp-on ammeter Amazon
- tachometer P/N 042223 Amazon
- 12 volt battery Amazon
- starter test bracket Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Minimum rpm 4500
- Maximum Amps 50
- Nominal amp draw of starter in generator 60 amps
Full service-parts list: Generac GP1800 →, Generac GP3250 →, Generac GP5000 →, Generac GP5500 →, Generac GP6500 →, Generac GP7000 →, Generac GP8000 →
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.