Section  7 
Choke,  Shutdown  Control  and  Governor 
7-1.  CHOKE  TESTING  AND  ADJUSTMENTS  (3.5kW, 
4.5kW  SINGLE) 
A 
WARNING 
BACKFIRE!  A  sudden  backfire  can  cause  serious  burns. 
Keep  hands  and  face  away  from  the  carburetor  when  the 
air  cleaner  is  removed. 
7-1.1 
General.  When  the  engine  start  switch  is activated, 
battery  current  activates  the  rotary  solenoid  in  the  electric 
choke  unit  (Figure  7-l).  The  choke  lever  pushes  the  choke 
plate  into  the  full  choke  position.  The  solenoid  deenergizes 
immediately  after  the  switch  is released  from  the  start  posi- 
tion.  When  the  solenoid  deenergizes,  the  choke  plate  opens 
to  a  position  determined  by  a  thermostatic  spring  and  the 
ambient  temperature.  As  the  engine  warms  and  less choking 
is  needed,  the  thermistor  circuit  allows  the  choke  plate  to 
gradually  move  to  full  open  position. 
A 
WARNING 
UNINTENTIONAL  STARTING!  To  prevent  accidental 
starting  when  checking  choke  operation,  remove  spark 
plug  lead(s)  at  spark  plug(s). 
A 
WARNING 
FLASH  FIRE!  Asudden  flash  fire  can  cause  serious  burns. 
To  avoid  the  possibility  of  a  flash  fire,  do  not  smoke  or 
permit  flame  or  spark  to  occur  near  carburetor,  fuel  line, 
fuel  filter,  fuel  pump,  or  other  potential  sources  of  spilled 
fuel  or  fuel  vapors. 
7-1.2.  Inspection. 
1.  Disconnect  the  high  tension  lead  from  the  spark  plug 
so the  engine  will  not  start. 
2.  Remove  the  air  cleaner  cover,  element  and  base  plate. 
3.  Push  the  start-stop  switch  on  the  controller  to  the  start 
position  and  hold  for  five  seconds.  The  choke  plate  should 
CHOKE 
SHAFT 
/ 
ONE  LEAD  TO 
STARTER  RELAY 
THE  OTHER  LEAD 
TO  CONTROLLER 
HEATER 
(THERMISTOR) 
TERMINAL 
LOCKWASHER 
IDLE  FUEL 
ADJUSTMENT 
SOLENOID 
TABS 
AUTOMATIC 
ELECTRI-CHOKE  UNIT 
I 
LEVER 
l/2  TURN  TENSION 
SPRING 
Figure  7-1.  Choke  and  Carburetor  (3.5KW,  4.5KW) 
7-l