Test or Inspection
Step 1. Check engine for hard starting or blow back
indicating possible ignition spark out of time.
Step 2. Check for part of the air shroud removed from the
Step 3. Check for restrictions in the exhaust.
Step 1. Inspect for a loose or broken spark plug.
Tighten spark plug. Replace a broken spark plug
by removing the coupling nut (2, fig. 4-8) and
removing plug (1).
Step 2. Check the valve adjustment with an 0.012 in.
(0.0305cm) feeler gage.
Adjust the valves as follows:
a. Turn the crankshaft over by hand until the lifter
(6, fig. 4-13) that is to be adjusted is at its lowest
Figure 4-12. Idle adjusting screw.
b. Insert 0.012 in. (.0305cm) feeler gage (5)
between the valve stem (8) and lifter screw (7).
Hold lifter (6) with wrench, and turn lifter
adjusting screw into or out of the lifter with
another wrench until the correct clearance is
obtained. A slight drag should be felt as the
feeler gage is moved back and forth.
Power Loss In Engine
Step 1. Check for a partly closed carburetor choke.
Open choke as follows:
so that there is still enough drag to rotate the
choke control shaft.
b. Lift up on the control lever (2) until the
carburetor choke control lever (3) is in the up, or
c. Tighten the clamp screw (1).
d When the lever (2) is released it should go back
to the intermediate position.
Step 2. Inspect for dirty air cleaner parts.
Remove, disassembly and clean or replace parts
Step 3. Check instruments and observe sluggish engine
Correct operation of cylinder filling unit
Pressure Vessel Pressure Too High, Alarm Bell
Does Not Ring
Step 1. Inspect tank alarm pressure switch out of adjustment
(The correct setting is 305 on the high side (knob 5) and 295
Air shroud heat deflector
on the low side (knob 6).
Adjust setting of the pressure switch as follows:
turning the adjusting knobs (5 and 6) to the desired
setting on the scale. Set the pressure switch (8),
Figure 4-13. Tappet adjustment.
connected to the conversion heater, at 275 on the
high side and 260 on the low side.