Order this information in Print

Order this information on CD-ROM

Download in PDF Format

     

Click here to make tpub.com your Home Page

Page Title: GENERAL INFORMATION
Back | Up | Next

Click here for a printable version

Google


Web
www.tpub.com

Home


   
Information Categories
.... Administration
Advancement
Aerographer
Automotive
Aviation
Combat
Construction
Diving
Draftsman
Engineering
Electronics
Food and Cooking
Math
Medical
Music
Nuclear Fundamentals
Photography
Religion
USMC
   
Products
  Educational CD-ROM's
Printed Manuals
Downloadable Books
   

 

ENGINE DIVISION SERVICE MANUAL TM 5-4210-230-14&P-1 GENERAL GENERAL INFORMATION The   outward   appearance   of   4150   series   carburetors described   in   this   service   manual   differ   with   engine   model, vehicle   model   or   year.      Manually   and   automatic   operated chokes  are  used  on  the  model  4150  and  4150C  respectively. The  centrifugal-vacuum  type  governor  is  used  on  the  model 4150G and the electronic vacuum modulating governor is used on the model 4150EG carburetor. The  model  4150  series  carburetor  is  of  the  four-barrel, two   stage,   downdraft   type.      The   first   stage   (primary   stage) supplies a fuel/air mixture throughout the entire range of engine operation and contains the choke valve.  The secondary stage constantly   supplements   the   fuel   delivery   as   needed.      The secondary  throttle  plates  are  vacuum  controlled  and  operated by the primary stage and governor. There  are  three  major  subassemblies  of  the  carburetor and they are: 1) the main body assembly, 2) the fuel bowls and metering assemblies, and 3) the throttle body assembly. The die-cast fuel bowls and metering bodies contain the fuel   chambers,   fuel   inlet   needle   valves,   accelerating   pump, primary  and  secondary  main  jets  and  fuel  metering  passages. The  die-cast  throttle  body  assembly  contains  the  primary  and secondary  throttle  plates,  throttle  linkage  and  various  fuel  and vacuum passages. A  diaphragm-type  operated  accelerator  pump  is  located in the bottom of the fuel bowl.  The pump functions when pump lever   is   activated   by   cam   on   throttle   lever   assembly.      An override    spring    on    pump    lever    adjusting    screw    allows    a prolonged discharge of fuel for smooth acceleration CARBURETOR SYSTEMS The primary side of the carburetor utilizes four basic fuel metering systems.  The Idle System provides, supplemented by the    secondary    side,    a    mixture    for    idle    and    low    speed performance.  The Accelerator System provides additional fuel during   acceleration;   the   Main   Metering   System   provides   an economical   mixture   for   normal   cruising   conditions;   and   the Power Enrichment System provides a richer mixture when high power output is required. In  addition  to  these  four  basic  systems,  there  is  a  fuel inlet system that constantly supplies fuel to the basic metering systems  and  a  choke  system  which  temporarily  enriches  the mixture to aid in starting and running a cold engine. The secondary side of the carburetor utilizes, depending on engine model, two or three basic fuel metering systems. The Idle  System  supplements  the  primary  side  to  provide  a  rich mixture  for  smooth  idle  and  low  speed  performance;  the  Main Metering    System    provides,    with    the    primary    system,    an economical cruising mixture; and the Power Enrichment System (not  used  on  all  carburetors)  provides  a  richer  mixture  when required. In addition to the basic secondary systems, there is also a fuel inlet system to supply fuel to the metering systems. Fuel Inlet System Fuel  enters  the  fuel  bowls  through  a  filter  screen  in  the fuel   inlet   and   into   the   fuel   inlet   valves   which   are   frequently referred to as the fuel inlet needle and seat assembly (Fig. 6). The amount of fuel entering the fuel bowls is determined by the space between the top of the movable needle and its seat and also  by  the  pressure  from  the  fuel  pump.    Movement  of  the needle in relation to the seat is controlled by the float and lever assembly which raises and falls with the fuel level.  As the fuel level  drops,  the  float  drops,  opening  the  needle  valve  to  allow fuel to enter the float chamber. When the fuel reaches a specified level, the float moves the needle valve to a position into the seat where it restricts the flow  of  fuel,  admitting  only  enough  to  replace  that  being  used. Any   slight   change   in   the   fuel   level   causes   a   corresponding movement  of  the  float,  opening  or  closing  the  fuel  inlet  needle valve to immediately restore or hold the correct fuel level. The   fuel   inlet   system   must   constantly   maintain   'the specified  level  of  fuel  as  all  the  other  metering  systems  are calibrated to deliver the proper mixture only when the fuel is at this level. Prior to the introduction of the emission control systems, most  all  fuel  bowls  were  vented  to  the  atmosphere.    On  later model carburetors, fuel bowls are vented internally and vapors are burned in the engine.   CGES-125-T  Page 3 PRINTED IN UNITED STATES OF AMERICA

Privacy Statement - Press Release - Copyright Information. - Contact Us - Support Integrated Publishing

Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business