TM 5-3810-300-24&P-3
14
SECTION 14
ENGINE TUNE-UP
CONTENTS
Engine Tune-Up Procedures ....................................................................................................
Exhaust Valve Clearance Adjustment ......................................................................................
Fuel Injector Timing ..................................................................................................................
Limiting Speed Mechanical Governor and Injector Rack Control Adjustment:.........................
Single and Double-Weight .................................................................................................
Dual Range ........................................................................................................................
Variable Low-Speed...........................................................................................................
Fast Idle Cylinder ...............................................................................................................
Fuel Modulating Governor and Injector Rack Control Adjustment ...........................................
Supplementary Governing Device Adjustment:........................................................................
Engine Load Limit Device ..................................................................................................
Power Control Device ........................................................................................................
Throttle Delay Mechanism .................................................................................................
Governor Shutdown Solenoid ............................................................................................
ENGINE TUNE-UP PROCEDURES
There is no scheduled interval for performing an engine
Normally, when performing a tune-up on an engine in
tune-up.
As long as the engine performance is
service, it is only necessary to check the various
satisfactory, no tune-up should be needed.
Minor
adjustments for a possible change in the settings.
adjustments in the valve and injector operating
However, if the cylinder head, governor or injectors have
mechanism, governor, etc. should only be required
been replaced or overhauled, then certain preliminary
periodically to compensate for normal wear on parts.
adjustments are required before the engine is started.
The type of governor used depends upon the engine
The preliminary adjustments consist of the first four
application.
Since each governor has different
items in the tune-up sequence. The procedures are the
characteristics,
the
tune-up
procedure
varies
same except that the valve clearance is greater for a
accordingly. The following types of governors are used:
cold engine.
1. Limiting speed mechanical.
NOTE: If a supplementary governing device,
such as the throttle delay mechanism, is used, it
must be disconnected prior to the tune-up. After
3. Fuel modulating.
the governor and injector rack adjustments are
completed, the supplementary governing device
The governors are identified by a name plate attached to
must be re-connected and adjusted.
the governor housing. The letters D.W.-L.S. stamped
on the name plate denote a double-weight limiting speed
To tune-up an engine completely, perform all of the
governor. A single-weight variable speed governor name
adjustments, except the valve bridge adjustment on a
plate is stamped S.W.-V.S.
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