Engine 168f DIY repair

Like any technique, a walk-behind tractor requires timely maintenance and repair. And it is advisable to entrust their implementation to specialists who have the necessary tools and equipment and know their job well. However, if you are also familiar with the device of internal combustion engines and understand the topic of mechanical engineering, then you can do a lot of what may be required to restore the machine's performance on your own.

Diesel and gasoline engines have different motor resources. For the former, the normal figure is 4000 m3 / h, but the latter are capable of providing only 1500 m3 / h. Despite this, diesel models of walk-behind tractors are not in high demand. After all, both when buying and during operation, they are much more expensive. Therefore, most likely you are working with a walk-behind tractor equipped with a gasoline (carburetor) engine.

All breakdowns that may arise during the operation of agricultural mini-equipment can be conditionally divided into two categories:

1. Engine malfunctions:

• startup problems;
• malfunctions.

1. Malfunctions of other units and mechanisms:

• improper clutch operation;
• breakdowns in the gearbox;
• problems with the chassis;
• malfunctions of control and automation;
• malfunctions of walk-behind tractor systems (cooling, lubrication, etc.).

In many ways, the success of repairing a suddenly out of order machine depends on the correctness of the diagnostics. With regard to maintenance, it is carried out precisely in order to identify small malfunctions, which subsequently lead to serious ones.

If you do not have the necessary knowledge, premises, tools and materials necessary for servicing and repairing the motor, entrust the work to a specialist!

If attempts to start the walk-behind tractor were unsuccessful, this means that there are malfunctions in the engine or starting system. In order to determine the source of the breakdown, you first need to check the spark plugs.

If the spark plugs are dry, this means that the fuel mixture is not entering the engine cylinders. There may be several reasons for this:

• there is no fuel in the tank;
• the fuel supply valve is closed;
• the hole in the gas tank plug is clogged;
• foreign objects have entered the fuel supply system.

To fix problems with the fuel supply, you must:

1. Fill the tank of the walk-behind tractor.
2. Open the fuel cock.
3. Clean the drain hole located in the fuel filler cap.
4. Remove the fuel cock, drain the fuel tank and rinse it with clean gasoline. After that, remove the connecting hose on the side of the carburetor and blow it out together with the carburetor nozzles without disassembling the latter using the fuel pump.

If fuel enters the carburetor but does not reach the cylinder, the problem is with the carburetor itself. To eliminate it, this unit must be removed, disassembled and cleaned. Well, after that - assemble and install in place. Therefore, before performing all the necessary manipulations, it does not hurt at all to refresh the memory of the device and the principle of operation of the carburetor.

In the event that, when checking the candles, they turned out to be wet, i.e. fuel is supplied normally, but the engine does not start, the problem may be as follows:

1. Failure of the ignition system:

• there is a characteristic carbon deposit on the spark plug electrodes (it is necessary to clean the candles with emery, after which they should be rinsed with gasoline and dried);
• the size of the gap between the electrodes does not correspond to that specified by the manufacturer in the engine operating manual (the gap is adjusted by bending the side electrode to the required dimensions);
• insulators for spark plugs or high-voltage wiring are damaged (defective plugs and wiring must be replaced);
• the STOP button is shorted to ground (for normal engine start, the short circuit must be removed);
• contacts in the angles of the candles are broken (contacts should be put in order);
• the gap between the magnetic shoe and the starter does not correspond to the standard value (gap adjustment is required);
• defects are found on the stator of the ignition system (the stator must be replaced).

1. Air leaks through the seals of the carburetor, spark plugs, spark plug heads and cylinders, as well as the carburetor and engine cylinder connections.

If a leak is detected in the connections, it is necessary to tighten the fastening bolts, tighten the spark plugs and check the integrity of the gaskets between the plug heads and the cylinders.

1. Incomplete closure of the carburetor choke.

To eliminate this problem, it is necessary to ensure free movement of the damper by checking the quality of the drive. If jams are found, they must be eliminated.

Compression and carburetor malfunctions

It so happens that the launch is carried out, but its process is significantly complicated. At the same time, the engine of the walk-behind tractor is extremely unstable and cannot develop power sufficient for normal operation.

The reason for this may be loss of compression, which can be identified by:

• soot on the working surfaces of the valves, as well as the seats of the cylinder blocks;
• deformation of the intake valve;
• wear of the piston rings.

In order to restore compression, you must:

1. Check the technical condition of the engine timing mechanism, clean the parts contaminated with carbon deposits, and if there are any defects, replace them.
2. Check the condition of the piston rings and replace defective components.

If, during engine operation, black smoke comes out of the muffler, and an excess of oil is detected on the spark plug electrodes, or they themselves are covered with carbon deposits, this means that:

• an oversaturated fuel mixture is fed to the carburetor;
• the sealing of the carburetor fuel valve is broken;
• the oil scraper ring of the piston is worn out;
• the air filter is clogged.

To fix this problem, you should:

1. adjust the carburetor;
2. replace the leaky valve;
3. replace worn piston rings;
4. clean or replace a defective air filter.

In the event that, when the engine is running, light smoke comes out of the muffler, and the spark plug electrodes are dry and covered with a white coating, this means that a lean fuel mixture enters the carburetor. This problem is eliminated by adjusting the carburetor operation.

Units and components of motors that are installed on agricultural mini-machinery are exposed to significant loads. They can also fail during the operation of the unit, which will very quickly lead to serious failures.

If suspicious noises, jerks and irregularities in the operation of the walk-behind tractor systems are detected, it is very important to immediately turn off the engine, and then let it cool down - only after that it will be possible to fix the problem.

If, during operation, the motor starts to gain momentum on its own, i.e. is "running out", most likely this means that the fastening of the regulator and traction levers is loose. In this case, the user will have to readjust the motor control drive.

Sometimes, when the throttle is fully open, the engine does not accelerate when the throttle is pressed, but on the contrary begins to lose power until it stops completely. This is a clear sign of overheating, so the walk-behind tractor must be turned off and wait until its components have completely cooled down. After that, you should check the oil level in the crankcase, and also check the cleanliness of the ribbed surfaces of the blocks and cylinder heads.

With increased engine loads, it can jam. There may be several reasons for this:

• not enough oil in the crankcase;
• a nadir formed on the lower head of the connecting rod;
• the connecting rod or oil spray is completely out of order.

If the motor of the walk-behind tractor is jammed, it will have to be disassembled and the condition of the main units and components should be checked: faulty, deformed, melted, etc. subject to replacement.

What to do if the motor block motor works intermittently and does not develop the required power? There may be several reasons for this behavior:

Air does not enter the carburetor, which means that the fuel does not burn well - the filter will have to be cleaned or changed.

Fuel residues and combustion products form a thick deposit on the inner walls of the muffler, which must be removed.

In this case, the assembly will have to be removed, disassembled and properly cleaned all of its components. After that, the carburetor must be assembled and properly adjusted.

1. Wear of the cylinder-piston group.

Temperature and high loads do their job, and even the most durable metal wears out and deforms over time. Such parts should be replaced immediately, otherwise you can pay for this with irreparable damage in the engine itself.

1. Damaged ratchet housing or ratchet

The presence of this problem is indicated by the lack of movement of the crankshaft when the engine is started. To replace the clutch housing and ratchet, you will have to completely disassemble the starting block.

1. Loosen the screws securing the starter housing to the engine housing.

If the starter cord does not return to its original position, the starter motor must be adjusted. To do this, the screws are loosened and the position of the knot is set by hand so as to ensure the normal return of the cord.

A fairly common reason for the lack of a return stroke of the starter cord is the failure of the starter spring - it will have to be replaced.

The service life of any equipment is significantly increased by competent maintenance of its main units and components. The promptness of replacing worn-out spare parts is also of great importance. Therefore, in the event of the slightest malfunctions and malfunctions, they should be eliminated immediately - as a result, this will prevent much more serious and expensive problems.

Lifan 168 f-2 engines with a maximum power of 6.5 hp. some of the most popular for installation on walk-behind tractors. They are used both on Russian-made motor vehicles and other manufacturers.

The Lifan 168 F-2 gasoline engine is designed for installation on small household motor vehicles. It is best suited for installation on cultivators and walk-behind tractors, motorized towing vehicles, motor pumps, generators, snow blowers and other equipment. This model combines durability, economy with reasonable cost and ease of use. Country of origin - China.

According to the statistics of Yandex requests, engines for Lifan walk-behind tractors are leading in terms of their popularity and demand. While Honda, Subaru and B&S are arguing over who is the best, Lifan is conquering the market in this segment. If you decide to buy a certain model through the online store, you will see that it is easier to buy and choose Chinese engines, since much more firms sell them.

For those who have equipment with an outdated engine, the engine for the Lifan 168F-2 walk-behind tractor, with an increased service life, is ideal for retrofitting. For a complete re-equipment, you just need to purchase a 2-strand pulley, platform, belts, throttle cable and a set of fasteners.

These engines are ideal for motoblocks presented in the Russian market Celina, Neva, Salyut, Favorit, Agat, Kaskad, UGRA, Oka, Volga, Luch, Farmer, Patriot. Almost all of the listed manufacturers equip their walk-behind tractors with Lifan gasoline engines.

For all Lifan equipment, we provide a 2-year warranty - this fact speaks of a fairly high quality.

Lifan (Lifan) - the official website of dealers in Russia:

The official representative of the LIFAN plant in Russia -

Official representative of LIFAN in Russia

All engines from the series Lifan 6.5 l c (the series includes Lifan 168F-2, 168F-2R, 168FD-2R) are equipped with an automatic decompressor and oil level sensor.The decompressor is used to reduce the effort when starting the engine, and the sensor is used in the engine blocking system when the oil level drops below the established norm.

Graph of dependence and torque on engine speed

From the graph we see that the optimal engine operating modes are around 2500 rpm

What type of oil to fill in the Lifan 168F-2 engine

The most correct choice of oil will help determine the operating instructions for the engine. Here is an excerpt from the instructions:
• Oil is a key factor in engine performance. Do not use additives and 2-stroke oil as they do not contain enough lubricant, which reduces the life of the engine.
• Check the engine by placing it on a horizontal surface
Recommended oil: SAE - 30 year old, SAE - 10W - 30 multigrade (see fig) Since viscosity varies with temperature and region, the lubricant should be selected according to our recommendations. See fig.
1. Place the engine on a level surface.
2. Remove the dipstick and wipe it clean.
3. Reinsert the dipstick into the neck of the oil sump without screwing in the cap and measure the oil level.
4.If the oil level is low, top up with the recommended engine oil.
5. Insert the dipstick into place.

The engine is equipped oil quantity control system (oil gauge)
The oil quantity control system is designed to prevent engine damage due to insufficient oil in the crankcase. When the oil level becomes insufficient, the oil quantity control system will automatically stop the engine, preventing engine damage, while the engine switch remains in the “ON” position.

The oil sensor is an element of the system that blocks the engine when the oil level drops below a certain limit. Engine blocking is needed:
- when overturning or overturning a vehicle.
- Lifan engines are installed as driving not only in vehicles, but also in generators. Generators, as a rule, are stationary mechanisms; long-term monitoring of their work is not required. Therefore, if something happens to the generator oil during operation, the blocking system will prevent its breakdown.

Use unleaded gasoline with an octane rating of at least 92. The use of unleaded gasoline reduces sludge formation and prolongs engine life. Never use unrefined gasoline or a mixture of gasoline and oil. The fuel must be free of dirt and water. Installed Japanese carburetor. The engine runs stably even on low quality gasoline.
If you decide to use gasoline containing alcohol (gasohol), make sure that its octane number is not lower than the recommended one. There are two types of gasohol, one containing ethanol and the other containing methanol. The ethanol content should not exceed 10%, and the methanol content should not exceed 5%. If there is more than 5% methanol in the mixture, it can reduce the efficiency of the engine, and, moreover, damage metal, rubber and plastic parts.

It is possible to purchase a certified gas module that makes the engine dual-fuel gas - petrol. In this case, the manufacturer's warranty remains.

Recommended spark plugs: BP6ЕS, BPR6ES (NGK) or NHSPLD F7RTCU. The cleanliness of the plug ensures that the engine runs smoothly and that carbon deposits do not form around the plug. Measure the spark plug gap with a feeler gauge. The gap should be between 0.7 and 0.8 mm. Adjust the distance by bending the side electrode.

Check that the spark plug washer is in good condition, replace if necessary. Screw in the plug by hand until it stops, and then tighten it with the special wrench. When you install a new spark plug, tighten an additional 1/2 turn to tighten the washer. If you are installing a plug that you have already used, tighten it 1 / 8-1 / 4 turn.
WARNING
• The candle must be carefully installed and pressed down.An insufficiently tightened spark plug can overheat and damage the engine.
• Use only recommended plugs and similar. An incorrect spark plug temperature range can damage the engine. Screw in the spark plug carefully so as not to break the threads in the cylinder block.

An important feature of the engine is that it is unified with many similar motors and the mounting platform mounts are the same, which does not cause difficulties when replacing the engine. The fact that Lifan is a copy of Honda (even sometimes licensed) is often mentioned - but this is not true. This information is announced by representatives of Honda.

Installation dimensions of the engine for the lifan 168f-2 walk-behind tractor:

Varieties of engines Lifan 168F-2

The different delivery options differ:

• diameter and type of output shaft
• type and type of gearbox (1/2, 1/6, chain, gear, with automatic centrifugal clutch)
• the presence of an electric starter and a lighting coil

Lifan 168F-2 The cheapest configuration with a shaft connection dimension of 19 or 20 mm.

Lifan 168F-2 The power unit has a tapered shaft outlet, it differs from the base model only in the tapered groove of the crankshaft nose, which provides a more accurate and tight fit of the pulleys.

Lifan 168F-2L This motor has a built-in reduction gearbox with an output shaft diameter of 22 mm

WHAT YOU NEED A REDUCED ENGINE REDUCER

- reduces the speed of rotation of the motor shaft, so in the presence of a gearbox - 1800 rpm, without a gearbox - 3600 rpm
- it is important to understand that the reduction gear does not increase the engine power, but increases its torque with a decrease in its rotation speed. Thus, the rated motor power remains practically unchanged.

Lifan168F-2R The motor is also equipped with a reduction gear, but with an automatic centrifugal clutch, and the size of the gearbox output shaft landing is 20 mm.

Lifan 168FD-2R 7A The most expensive version of the engine is distinguished not only by the diameter of the gearbox output shaft increased to 22 mm, but also by the presence of an electric starter. The rectifier required to charge the battery is not included in the scope of delivery.

Here are some examples of engine modifications:

Decoding of the marking of Lifan engines

The brand name is followed by a series of engine, which is indicated by the corresponding numbers and letters, from which you can determine the power, measured in horsepower:

- 152 - 2.5 l / s;
- 160 - 4 l / s;
- 168 - 5.5 l / s;
- 168-2 - 6.5 l / s;
- 170 - 7 l / s;
- 173 - 8 l / s;
- 177 - 9 l / s;
- 182 - 11 l / s;
- 188 - 13 l / s;
- 190 - 15 l / s;
- 192 - 17 l / s;
- 2V78F-2 - 24 l / s two-cylinder;
- 1P60 - 4 l / s vertical shaft
- 1P64 - 5 l / s Vertical shaft
- 1P70 - 6 l / s vertical shaft

- C178 - 6 l / s;
- C186 - 10 l / s;
- C188 - 13 l / s.

The series number in the name is followed by Latin letters, their meanings are as follows:

F is the standard engine. Example: Lifan 168 F is a 168 series motor as standard with normal manual start.

D - designation of the electric starter. Example: Lifan 168 FD - 168 series engine with manual and electric starter.

R - designation of a reduction chain gear with a centrifugal clutch. Example: Lifan 168 F-R is a 680 series motor with manual start, chain reducer and centrifugal clutch. Missing D indicates manual start. Lifan 168 FD-R - electric start, chain reduction gear and centrifugal clutch. A centrifugal clutch is the rotation of a shaft as rpm increases. The more gas you give, the stronger the shaft rpm.

L - a gear reducer is located on the engine. Example: Lifan 168 F-L is a 168 series motor with an installed gear reducer that halves the standard speed.

S - the motor is designed for use at low temperatures, ideal for winter. For example: the Lifan 188 FD (S) engine is a unit of the 188 series with electric start, in the winter configuration.

H - a chain reducer is installed on the engine.Example: Lifan 168 FH is a 168 series motor with an installed chain reducer that halves the standard speed.

V - engine with a vertical crankshaft. Example 1P 54FV - 1P 54 - motor series, F - standard manual start, V - vertical shaft.

C - diesel engine.

In some cases, in the marking of Lifan engines, in particular the 168 series, you can see the letter B, For example Lifan 168F-2B... The presence of this letter in the name means that the appearance (design) of the engine has been changed.

The color of Lifan engines can be changed at the request of the supplying organization of the corporation. Lifan Industry Group Co. Ltd. (reservation: provided that the batch of engines will be over 1100 pcs.).