1100 — Generac 1100 — Overcrank (Engine Failed to Start)
Alarm 1100 is Overcrank: the engine cranked through all of its start attempts but failed to start, so the controller stopped trying. It is NOT a low-oil-pressure code (that is 1300). (Meaning corrected against official Generac support documentation / Evolution controller e-code list; older Nexus controllers may differ — confirm for your unit.)
- Keep using it?
- Limited use only
- DIY difficulty
- Moderate
- Verified against
- support.generac.com ↗
How to fix it
- Confirm the fuel supply: gas shutoff valve fully open, adequate LP/natural-gas pressure.
- Load-test the starting battery and check connections.
- Inspect and re-gap or replace the spark plugs.
- Attempt a manual start; if it still overcranks, have a dealer check fuel delivery.
Why it happens
Typical signs: Generator will not start during an outage or exercise · 1100 / Overcrank in the alarm log · Engine cranks but does not fire
- No fuel / gas supply Closed gas shutoff valve, low gas pressure, empty/low LP tank, or a fuel regulator problem.
- Weak or dead starting battery Not enough cranking power to start.
- Fouled or worn spark plugs Weak spark prevents starting.
- Fuel delivery / mixture fault Choke, solenoid, or carburetor issue.
Parts you may need
If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.
More Generac generator codes
Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: support.generac.com.