Detroit Diesel — Adjust Maximum No-Load Engine Speed (Standard Limiting Speed Mechanical Governor)
Adjustments
From a Detroit Diesel service manual — check it applies to your exact model before use.
Procedure
- Loosen the spring retainer lock nut and back off the high-speed spring retainer approximately five turns.
- With engine running at operating temperature and no load, place speed control lever in maximum speed position; turn high-speed spring retainer to recommended no-load speed.
- Hold the high-speed spring retainer and tighten the lock nut.
Tools required
- Tachometer Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Buffer screw must project 5/8 in from lock nut
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.