Cummins/Onan JWC4-10S-3 — Adjusting the Engine Governor
Adjustments
For the Cummins/Onan JWC4-10S-3, from the Cummins/Onan service manual.
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Procedure
- Run engine at normal operating temperature.
- Adjust length of throttle control rod so carburetor throttle lever clears wide-open stop by 1/64 in.
- Loosen bumper spring screw locknut and turn screw out to prevent functioning; loosen spring slide shoulder screws.
- Start engine and turn spring slide adjusting screw to obtain correct speed.
- If governor surges under load, adjust governor spring eyebolt downward until surging stops.
- If governor surges at no load, turn bumper spring screw in until surging stops.
- Tighten all locknuts and shoulder screws.
Tools required
- Wrenches Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- At no load voltage should not exceed 235 V
- At full load voltage should not be lower than 215 V
Source: Cummins/Onan 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.