Onan NHC Series Operator's/Service Manual And Parts Catalog page 290

Rotating the choke body clockwise richens and
counterclockwise leans the choking effect. For am-
bient temperatures above 85° F, the choke should be
fully opened. For ambient temperatures below 25° F,
the -choke should be opened 1/4 inch with the
solenoid not engaged. Tighten the screw that secures
the choke body.
If the choke will not close, check for binding,
incorrect adjustment, or incorrect assembly of the
bimetal and heater assembly. If the choke will not
open after the engine starts, check for heating. The
choke bimetal should be warm to the touch within a
minute or two after starting.
To disassemble the choke, refer to Figure 19.
If the heater assembly will not heat properly, check for
broken heater wire, high resistance connections or
broken lead wires to the bimetal and heaterassembly.
With the element at room temperature, check the
heater resistance with an ohmmeter. The resistance
should beabout37.8to 46.2ohms fora 12 volt system.
If the heater is defective,
r
replace. There must be slack
in the lead wires between the choke body and the
bimetal and heater assembly. When the start button is
engaged, the solenoid should cause the spring load-
ed lever to contact the solenoid core. If this does not
occur, check for broken lead' wires or a defective
solenoid core.
The solenoid coil should have a resistance of 2.09 to
2^31 ohms in a 12 volt system.
Assembly: Refer to Figure 19. When assembling the
thermomagnetic choke, connect the bimetal and
heater assembly as follows:
1. Lead tagged G to ground terminal in coil
solenoid.
2. Lead tagged H to either of the HI terminals on the
solenoid core.
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