Section 13: Troubleshooting - Generac Power Systems GN190H Service And Repair Manual

PROBLEM
1. Engine will not start or starts
with difficulty.
2. Engine knocks.
3. Engine misses under load.
4. Engine lacks power.
5. Engine overheats.
6. Engine vibrates excessively.
POSSIBLE CAUSES
a. Fuel tank is empty.
b. Low oil level.
c. Dirty air cleaner.
d. Obstructed fuel Line.
e. Fuel tank cap vent hole is obstructed.
f. Spark plug is fouled.
g. Incorrect spark plug.
h. Loose or defective ignition wiring.
I. No ignition spark.
j. Incorrect valve clearance.
k. Poor compression.
a. Carbon in combustion chamber.
b. Loose flywheel.
c. Worn cylinder.
d. Loose or worn connecting rod.
e. Incorrect valve clearance
a. Incorrect spark plug.
b. Spark plug is fouled.
c. Spark plug porcelain is cracked.
d. Incorrect spark plug gap.
e. Incorrect valve clearance.
f. Weak valve springs.
a. Governor not set correctly.
b. Incorrect spark plug
c. Incorrect valve clearance.
d. Worn piston rings.
e. Low oil level.
f. Air cleaner is obstructed.
g. Valves or valve seats worn or burned.
a. Air flow is obstructed.
b. Cooling fins are clogged.
c. Carbon buildup in combustion chamber.
d. Engine is overloaded.
e. Lack of lubrication
a. Engine mounting bolts loose.
b. Bent crankshaft.
c. Problem in equipment
connected to engine.
53

SECTION 13: TROUBLESHOOTING

REMEDY
a. Fill fuel tank.
b. Replenish oil as necessary.
c. Clean or replace
air cleaner element.
d. Clean fuel line or replace.
e. Open cap vent hole.
f. Replace spark plug.
g. Replace with correct spark plug.
h. Check wiring, repair or replace.
I. Check ignition system, replace
defective part(s).
j. Reset valve clearance.
k. Check for worn or scored cylinder.
a. Clean carbon from head
and piston.
b. Check flywheel key and keyway,
replace part(s) if necessary. Tighten
flywheel nut.
c. Replace crankcase.
d. Replace connecting rod. Check
crankpin diameter to see if
crankshaft is bad.
e. Reset to correct clearance.
a. Install correct spark plug.
b. Clean and regap spark plug.
c. Replace spark plug.
d. Regap the spark plug.
e. Reset valve clearance.
f. Replace weak valve spring(s).
a. Adjust governor.
b. Install correct spark plug.
c. Reset valve clearance.
d. Replace piston rings.
e. Replenish oil to proper level.
f. Clean or replace air cleaner.
g. Grind valves and valve seats.
a. Remove obstructions
b. Clean cooling fine.
c. Remove cylinder head and
clean carbon.
d. Reduce excessive loading.
e. Replenish oil to proper level.
a. Tighten mounting bolts.
b. Replace crankshaft.
c. Check equipment driven
by engine.