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Warranty Time:

During the warranty time, customer will enjoy YARMAX power or local authorized distributor’s good service and maintenance.


Products Warranty:

Products warranty time based on the delivery time and running time. YARMAX power provide warranty time in the following tables, special terms could be settled in the contract.


Product warranty time


Delivery Time (Month)  Running Time (Hour)

Air Cooled Diesel Engine

15 1200

Small Diesel Generator

15 1200

Big Diesel Generator

15 1200

Welding Diesel Generator

15 1200

Water Pump

15 1200

Lighting Tower

15 1200


Wearing parts warranty time


Delivery Time (Month) Running Time (Hour)

Air Cooled Diesel Engine

8 600

Small Diesel Generator

8 600

Big Diesel Generator

8 600

Welding Diesel Generator

8 600

Water Pump

8 600

Lighting Tower

8 600


Warranty Contents:

During warranty time, products are used in correct way by customer, if there are malfunctions occur in engine/alternator/pump. YARMAX power or local authorized distributor wil be in charge of free check and preparing. Broken parts will be replaced by brand new spare parts,further more,products will be debugged well.


Warranty Charges:

All spare parts and labor cost will be paid by YARMAX power or local authorized distributor during warranty time. Customer will not take on any charges.


Response Time:

YARMAX power or local authorized distributor should response customers claims within 24 hours and provide the relative service.

Exceptions for Warranty:

Damages occur in customers transportation;

Damages occur from customers incorrect operation;

Damages occur from customers self-repairing during warrant time;

Damages occur in war,earthquake,hurricane etc irresistible;

Customer could not provide the warranty card or purchasing evidence.

Repair and Maintenance

1. General

A good maintenance program is the key to extending the genset’s lifetime. Maintenance and service should only be operated by qualified technicians. Records of this work should be kept to develop an efficient maintenance program.

2 Generator Set Preventative Maintenance

Check before starting every time ( For standby sets these procedures may be performed weekly.) A walk around inspection should be performed on a daily basis and prior to starting the engine.

Every two weeks:

( For standby sets that have not been run.) Perform an operational check on the generating set by starting and running the set for only takes 5 minutes. WARNING: don’t run diesel engines at low loads for long periods.


Every month

( For standby sets that have not been run on load. ) Perform an operational check on the generating set by starting and running the set on at least 50% load takes 1 to 2 hours.


Every six months or 250 hours

Repeat the daily procedures, as follows:

Check all control system safety devices by electrically simulating faults.

Clean all battery cap vents.

Tighten all exhaust connections.

Tighten all electrical connections.

Perform other engine maintenance as specified in the engine manual.

Start the engine and observe the instrument panel to ensure that ll gauges and meters are operating properly.


When diesel generator sets operate, in standby power or prime power, they perhaps encounter some mechanical or electrical problems which could cause them to either shutdown or degrade their performance. Generator set problems vary from simple electrical wiring faults to major engine problems. Trouble-shooting in the generator sets can simply answer these questions: What caused this alarm, or what caused this shutdown or what caused this erratic befavior. Trouble-shooting is a process of collecting the information and defining the problem. After defining the problem, list all the possible causes of the problem and finally select the solution to eliminate the problem, as well as taking the economics and reliability into consideration.

A. Malfunction and Troubleshooting for Diesel Engine

Trouble and Trouble shooting for the Engine Not Being Started


Trouble shooting

The cold Machine's oil is viscous

Fill machine oil into crankcase after warming-up
Fill machine oil into inlet pipe
Remove the connection belt from the machine
Start up the engine and stop it when it is heated and then restart the engine

Air exists in fuel system

Emit the air and tighten each connect part to the fuel pipe

Injection fuel is little or the spray is not excellent

Check the position of governing handle or check and clean the fuel nozzle or change the nozzle if necessary

Deficiency in pressure of compression

Loosen the nut of cylinder head
Damage or leakage of cylinder gasket Tighten the nut of cylinder head in the diagonal sequence; check the gasket of cylinder as the standard requirement. When the engine with the new gasket is heated, tighten the nut of cylinder head again


Trouble and Troubleshooting for Deficient Power of Diesel Engine


Trouble shooting

Malfunction of fuel system
Partial obstruction in fuel filter and fuel pipe
Inadequate fuel supplying

Check the fuel switch, they should be opened fully
Clean the fuel filter and fuel pipe

Bad pressing of fuel pump

Check or change the damaged parts of fuel pump

Malfunction of the fuel nozzle
Inadequate injection pressure

Adjust the injection pressure

Carbon deposit in the nozzle hole


Needle was bit

Clean or change

Loose fit between needle and needle body


Obstruction in air filter

Remove, clean or change the filter core

Not fast enough of engine speed

Check the speed of engine with the tachometer, and then readjust the speed of limit bolt


Trouble and Troubleshooting for Engine Stopping Automatically.


Trouble shooting

Malfunction of the fuel system or Run out of fuel

Fill fuel

Obstruction in fuel pip or air filter

Check or clean

Air exists in fuel system

Emit the air

Nozzle needle was bit

Clean, skive the nozzle or change it if necessary

Obstruction in air filter

Check, clean, brush off, or change the filter element

Sudden increase of load

Lighten the load


Trouble and Troubleshooting for Exhausting Black Smoke


Trouble shooting


Lighten the load and change the matched machine if it does not comply with the requirements

Bad spray

Check injection pressure and spray condition and then remedy; change the nozzle if it was damaged

Lack of air or leakage

Clean the air filter; check the cause of leakage and then remedy


Checking Methods when the Engine Encounters Malfunction


Trouble shooting

Speed sometimes is fast or slow

Check if the speed governing system is flexible, and if air mixed in oil pipeline

Abnormal noise suddenly sent out

Stop the engine and inspect each movable parts carefully

Exhaust turn black suddenly

Check fuel system, especially the nozzle

Rhythmically metal knocking sound in the cylinder

The fuel delivery angle is too big, should adjust the angle


B Overhaul and Troubleshooting for Diesel Generator


Trouble shooting

Lack of diesel fuel

Add diesel fuel

Oil switch is not on the position of "ON" (start switch)

Switch handle to the position of "ON"

No or little spray from injection pump and nozzle

Disassemble the nozzle and adjust it on the test table

The governor handle is not on the position of "RUN"

Turn the governor handle to the position of "RUN"

Check the lubricating oil level

The standard of lubricating oil is between upper line “H” and bottom line “L”

Recoil starter is not swift and powerful enough

Start the engine according to “ Start Operation Procedure”

The nozzle is dirty

Clean the nozzle

No electricity of storage battery

Charge up or change the storage battery


Trouble and Troubleshooting for the Generator not Running Automatically


Trouble shooting

Power switch is on the position of “OFF”

Turn the switch handle to the position of “ON”

Bad contact of the socket

Adjust the socket pins

Damage of capacitor

Change the capacitor