Detroit Diesel — Adjust Idle Speed (Mechanical Governors)
Adjustments
From a Detroit Diesel service manual — check it applies to your exact model before use.
Before you start
- Do not raise the engine idle speed more than 15 rpm with the buffer screw
Procedure
- With engine at normal operating temperature and buffer screw backed out, turn idle speed adjusting screw until engine operates at approximately 15 rpm below recommended idle speed.
- Hold the set screw (or former idle speed adjusting screw) and tighten the locknut.
- Install the high-speed spring retainer cover.
Specs & values
- approximately 15 rpm below recommended idle speed
Source: Detroit Diesel 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.