Onan CCK Service Manual

4. Connect or turn on fuel supply to regulator.
5. Check (smell) for propane leak's.
6. Start engine—it should start within 20 seconds if
fuel is available to carburetor.
FIGURE 31. INITIAL START ADJUSTMENT
CHECKING FOR FUEL AT CARBURETOR
[ WARNING ) Do not permit any flame, cigarette,
or other igniter near the iuelsystem.
Propane gas is highly flammable and potentially
explosive in confined spaces.
f. Disconnect fuel line at carburetor.
2. Momentarily, press primer button; you should
smell gas at end of fuel line. If not, check fuel lines
back to supply tank.
With experience, you should be able to feel gas pressure on
the regulator diaphragm when you press the primer button.
3. Look for one or more shutoff devices.
4. On vacuum operated shutoff valve systems, close
throttle (fully) to aid engine starting with better
vacuum.
5 If fuel is present at carburetor, check ignition
system or other engine malfunctions.
CARBURETOR ADJUSTMENTS WITHOUT
EXHAUST ANALYZER
1. Run new engine at least ten hours at normal
service load. Avoid high loads before proper
adjustments are made.
2. Run engine at maximum throttle and norma! load
for ten minutes, or set main power mixture near
mark between L and R as shown in Figure 31.
3 Set main power mixture as lean as possible
without noticeable loss in power output. If frost
develops and remains on regulator for more than
five minutes, check for propane leaks and ensure
that vaporizer coil wraps tightly around exhaust
pipe.
4. If engine functions properly but frost remains on
regulator, the carburetor power mixture is too
rich. Adjust for maximum efficiency.
5. Recheck head bolt torque and valve lash after
carburetor is adjusted.
IDLE SCREW AND IDLE STOP
1, R u n engine at idle speed (1200 rpm) for ten
minutes.
2. Adjust idle screw for maximum speed; maximum
speed should be attained when idle screw is
turned fully clockwise into carburetor.
3. Set idle stop screw speed at 1350 rpm..
4. Turn idle screw out until engine speed slows to
1200 rpm.
CARBURETOR ADJUSTMENTS WITH EX¬
HAUST ANALYZER
Exhaust analyzers (with at least ±3 percent accuracy} should be
infra-red equipment, but flame ionization can be used for measur¬
ing hydrocarbon emissions which are n-hexane equivalent All data
is based on dry measurements which are obtained after removing
all water vapor from the exhaust samples. A wet measurement will
be about 15 percent less than for a dry measurement, if none of the
water vapor is removed from the samples.
Main Power Adjustment:
1. Run engine at open throttle for normal maximum
rpm for ten minutes or set main power mixture at
mark between L and R as shown in Figure 31.
2. Adjust main jet for 1.0-pius 0.5-percent CO
emission.
3. If frost develops and remains on regulator for
more than five minutes, check for leaks and be
sure vaporization coil wraps tightly around ex¬
haust pipe.
When the fuel system functions properly, the regulator should
be frost free after about five minutes running time.
Idle Screw Adjustment:
1. Run engine at 1200 rpm for ten minutes.
2. Using idle stop screw and idle mixture screw, set
engine exhaust emissions for .2 s. 1 percent CO at
1200 rpm on richest mixture possible.
If this condition is met, the CO emission will exceed .5 percent
when idle screw is turned one half turn counterclockwise from
setting attained in step 2.
3. Return to 0.2 ± 0.1 percent CO idle screw setting.
At proper idle adjustment, the HC emission should be under
1000 ppm and CO 2 emission will be 8 to 10 percent.
THROTTLE STOP ADJUSTMENT
1. Adjust throttle stop clamp for maximum service
load; throttle should be 20 degrees from vertical
position at wide open th rottle. Th rottle travel from
open to closed position should be 50 degrees.
| caution^ Do not change the throttle stop
to increase the throttle open¬
ing. increasing the throttle opening beyond this
point does not increase the power output of the
engine because the carburetor is designed for
even larger engines. It may, however, adversely
affect governor operation .
2. Check throttle linkage for freedom of movement.
35

Onan CCK Specifications

General

Cylinders	2
Ignition System	Battery ignition
Fuel Type	Gasoline
Cooling System	Air-cooled
Fuel System	Carburetor
Starter	Electric
Governor	Mechanical
Max RPM	1800 RPM
Engine Type	4-cycle
Bore and Stroke	3.25 x 3.625 inches (82.55 x 92.08 mm)