Detroit Diesel — Adjust Starting Aid Screw (Internal, Turbocharged Engines)
Adjustments · Governor starting aid screw
From a Detroit Diesel service manual — check it applies to your exact model before use.
Before you start
- The effectiveness of the starting aid screw is eliminated if the speed control lever is advanced to wide open throttle during starting.
Procedure
- With engine stopped, place governor stop lever in run position and speed control lever in idle position.
- Hold gap adjusting screw and adjust starting aid screw for .330 to .360 in clearance between shoulder on No. 3R injector rack clevis and injector body.
- Note gap of .155 to .160 in between high speed spring plunger and low speed spring cap with engine stopped.
- Move stop lever to stop position and return it to run position.
- Recheck injector rack clevis-to-body clearance; adjust by backing out or turning in the starting aid screw.
- Start engine, recheck running gap (.0015 in), reset if necessary, then stop engine.
Tools required
- Feeler gage Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- .330 to .360 in clevis-to-body clearance
- .155 to .160 in governor gap when stopped
- .0015 in running gap
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.