Onan NHE Service Manual

Trouble
Engine
Lacks Power
Engine
Black Exhaust
TROUBLESHOOTING ENGINE PRIMARY SYSTEMS
Possible Cause
1. Faulty ignition due to:
a. incorrect ignition timing
b. incorrect spark plug gap
2. Dirty air cleaner
3. Restricted fuel flow due to:
a. plugged fuel filter or
b. faulty fuel pump
4. Incorrect fuel mixture due to:
a. incorrect adjusted
c. dirt in carburetor
fuel mixture screws,
*b. incorrect float level, or
5. Exhaust system blocked or
restricted
6. Incorrect valve tappet
clearance
7. Excessive engine wear or
8. Carburetor air preheater
damage to engine
set incorrectly
*Gasoline Sets Only
1. Restricted airflow due to
dirt or debris blocking air
inlet or outlet
2. Dirt or oil covering engine
cooling fins
3. Incorrect ignition timing
4. Lean fuel mixture due to
a. incorrectly adjusted
fuel mixture screws
"b. incorrect float level or
c. dirt in carburetor
*Gasoline sets only
1. Rich fuel mixture due to:
a. dirty air cleaner.
"b. choke sticking,
c. incorrectly adjusted fuel
mixture screws
d. dirt in carburetor
*Gasoline sets only
Corrective Action
la. Adjust breaker point gap
1 b. Reset spark plug gap
2. Replace air cleaner
3a. Clean fuel filter
3b. Test fuel pump and repair
or replace if faulty
4a. Adjust carburetor main and
and idle adjustment screws
4b. Adjust carburetor float level
4c. Disassemble carburetor and
clean all internal passages
5. Locate and remove cause
of blockage.
6. Adjust valve tappets (see
Engine Block Assembly section)
7. See Engine Block
Assembly section
8. In hot weather, place
air preheater in summer position
1.
Clear away any debris that
may restrict airflow to
set. Do not use compartment for
storage area.
2.
Clean away all dirt and oil
from engine cooling fins
3. Adjust breaker point gap
4a. Adjust carburetor main and
idle adjustment screws
4b. Adjust carburetor float
level
4c. Disassemble carburetor and
clean all internal passages.
la. Replace air cleaner
1 b. Clean choke and choke linkage
IC. Adjust carburetor idle and
main adjustment screws
Id. Disassemble carburetor and
clean all internal passages
I
6-2
Redistribution or publication of this document
by any means, is strictly prohibited.
Redistribution or publication of this document
by any means, is strictly prohibited.

Onan NHE Specifications

General

Brand	Onan
Model	NHE
Category	Portable Generator
Language	English