HomeGeneracGenerac MIH1.2

Generac MIH1.2 Generator Set

The Generac MIH1.2 is a Diesel generator set. It is available at 12 V. It holds about 7.1 L (1.9 gal) of oil and 2.1 L (0.6 gal) of coolant. Starting uses 1 group-24 battery rated 720 CCA at 12 V.

7.1 L
Oil capacity
1
Document types

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Specifications

FuelDiesel
Emissions4 Final
ControllerLOFA
Oil capacity7.1 L
Voltage options12 V
Battery group24
Battery cranking720 CCA
Battery voltage12 V
Battery quantity1
Coolant capacity2.1 L

Maintenance & consumables

ItemSpecCapacityPart #Interval
Air filterelement
Fuel filter
Oil filter250 hr
BatteryInspect battery monthly and recharge or replace as needed. Inspect system every six months.2160 hr
Belt500 hr
Coolant filterCoolant Drain Plug
OilDrain and refill oil every 500 hours or as needed.500 hr
Spark plug3000 hr

Common questions

What kind of fuel does the Generac MIH1.2 run on?

The Generac MIH1.2 runs on Diesel.

Troubleshooting

6

Symptoms & remedies

SymptomCauseRemedy
Engine does not crankLow battery output voltage or discharged battery. Loose or corroded connections. Faulty start circuit relay. Blown fuse. Faulty main switch or start safety switch. Faulty starter solenoid. Faulty starter.Charge or replace batteries. See Battery Inspection. Clean and tighten connections. Contact a GMASD. Replace fuse. Repair switch as required. Replace solenoid. Replace starter.
Starter cranks slowlyLow battery output voltage or discharged battery. Excessive crankcase oil viscosity.Charge or replace batteries. See Battery Inspection. Drain crankcase oil and replace with correct viscosity oil. See Draining and Refilling the Oil.
Hard to start, or does not startEngine starting under load. Incorrect starting procedure. Restricted exhaust. No fuel. Air in fuel line. Poor fuel quality. Water, dirt, or air in fuel system. Fuel filter restricted or full of water. Dirty or faulty fuel injectors. Electronic fuel system failure. Cold weather.Disengage PTO. Review starting procedure. See Pre-start Checklist and Engine and Heater Startup. Inspect and correct exhaust restriction. Check fuel tank. Purge fuel lines. See engine manual. Drain fuel and replace with proper grade and quality of fuel for operating condition. Drain, flush, fill, and purge fuel system. Replace fuel filter or drain water from fuel filter. Contact a GMASD. Use cold weather starting aids (see engine manual).
Engine misfiring or runs irregularlyPoor fuel quality; incorrect fuel/dirty fuel. Restricted fuel filter. Water, dirt, or air in fuel system.Test fuel, drain water from fuel bowl. Replace fuel filter element. Drain, flush, fill, and purge fuel system.
Lack of engine powerRestricted air intake. Restricted exhaust. Poor fuel quality. Restricted fuel filter. Engine overloaded. Incorrect crankcase oil. Low coolant temperature. Incorrect valve clearance. Dirty or faulty fuel injectors. Air leak in engine intake or exhaust manifold.Service air cleaner. Check and correct exhaust restriction. Drain fuel and replace with proper grade and quality of fuel for operating condition. Replace fuel filter elements. Reduce engine load. Drain crankcase oil and replace with correct viscosity oil. See Draining and Refilling the Oil. Remove and check thermostat. Adjust valve clearance or contact a GMASD. Check intake and exhaust manifold gaskets and manifolds; repair as required or contact a GMASD.
Engine idles poorlyPoor fuel quality. Electronic control system problem or basic engine problem.Drain fuel and replace with proper grade and quality of fuel for operating condition. Contact a GMASD.

Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full Generac MIH1.2 troubleshooting guide (42 entries) →

Available documents

Owner's manual — A0000244062 (Generac)