Miller Big Blue 400 PX CE Owner's Manual page 54

Trouble
Battery discharges between uses.
Engine idles, but does not come up to
weld speed (units with idle option only).
Engine does not run at idle speed
(units with idle option only).
Engine uses oil during run-in period;
wetstacking occurs.
Notes
OM-229 979 Page 48
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 fuel/hour gauge FUEL/HM and current transformer
CT1.
Check for obstructed throttle solenoid.
Check for obstructed throttle solenoid.
Circuit breaker CB9 may be open. CB9 automatically resets when fault is corrected (see Section 8-11).
Have Factory Authorized Service Agent check fuel/hour gauge FUEL/HM and control relay CR4.
Dry engine according to run-in procedure (see Section 10).
Remedy