Miller Electric Big Blue 502P Owner's Manual page 38

Trouble
Battery discharges between uses.
Engine idles, but does not come up to
weld speed (models with idle option
only).
Engine does not run at idle speed
(models with idle option only).
Engine uses oil during run-in period;
wetstacking occurs.
OM-491 Page 34
See engine manual.
Turn Engine Control switch off when unit is not running.
Clean top of battery with baking soda and water solution; rinse with clear water.
Recharge or replace battery if necessary.
Periodically recharge battery (approximately every 3 months).
Have Factory Authorized Service Agent check Engine Control switch S1.
Have Factory Authorized Service Agent check idle module PC7 and current transformer CT1.
Check for obstructed throttle solenoid.
Place Stick/TIG Selection switch in Stick position.
Check for obstructed throttle solenoid.
Have Factory Authorized Service Agent check idle module PC7, and control relays CR3 and CR6.
Dry engine (see Section 9).
Remedy