Do-it-yourself lifan engine repair

In detail: do-it-yourself lifan engine repair from a real master for the site my.housecope.com.

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 operability of the machine yourself.

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:

Engine malfunctions:

startup problems;
malfunctions.

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.

Video (click to play).

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:

Fill the tank of the walk-behind tractor.
Open the fuel cock.
Clean the drain hole located in the fuel filler cap.
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:

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).

Air leaks through the seals of the carburetor, spark plugs, plug and cylinder heads, 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.

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:

Check the technical condition of the engine timing mechanism, clean the parts contaminated with carbon deposits, and if there are any defects, replace them.
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:

adjust the carburetor;
replace the leaky valve;
replace worn piston rings;
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.

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.

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.

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 addressed immediately - as a result, this will prevent much more serious and expensive problems.

Motoblocks, like any modern technology, require constant maintenance. Otherwise, failure, frequent overheating of the internal combustion engine, and increased fuel consumption are possible. Such malfunctions of the walk-behind tractor are quite simply solved on their own, if you know the main reasons for their occurrence.

It should be noted that absolutely everyone can buy a walk-behind tractor today. There are many different models on the free market. Among them, motoblocks of the Lifan brand are very popular. They are practical, durable and reliable. However, if the engine fails, it must be repaired. So how to identify the malfunction of the engines of the Lifan walk-behind tractors and solve the problem with your own hands?

It should be noted that diesel and gasoline engines have different motor resources. Experts say that in the first case it is 4,000 m3 / h, in the second - 1,500 m3 / h. However, in practice, not everyone is in a hurry to buy a Lifan engine on a diesel engine. This is due to the higher purchase and operating costs. Accordingly, it is more expedient to describe in more detail the features of repairing the Lifan engine for a walk-behind tractor on gasoline.

All breakdowns are conventionally divided into 2 categories:

Problems associated with the operation of the internal combustion engine (its start-up, unstable operation of the engine of the walk-behind tractor, etc.).

Malfunctions in the operation of the other units of the walk-behind tractor (gearbox, chassis, automation, etc.).

The success of repair work often depends on the diagnostics and the quality of the spare parts used for your particular model of equipment. If you do not have minimal knowledge and skills, it is better to entrust the repair of the Lifan engine for a walk-behind tractor to specialists!

Can't start the walk-behind tractor? The problem can be with both the engine and the ignition system. Pay attention to the spark plugs. If they are still dry, there is a problem with the fuel supply to the engine. Here are the main reasons for this phenomenon:

the fuel supply valve is closed;

there is no fuel in the tank;

clogged hole in the gas tank;

a foreign object has entered the fuel supply system.

You can eliminate these moments as follows. Refuel the gas tank, open the fuel cock, clean the drain hole. Drain the gasoline tank, flush it with clean fuel, blow out the connecting hose and carburetor jets.

If fuel is supplied to the carburetor, but not in the internal combustion engine, in this case it will be necessary to remove it, disassemble, clean and put it back.

If, when inspecting the candles, there is moisture on them (fuel comes in), and the engine does not want to work, you should pay attention to the following points.

Perhaps the problem is a failure of the ignition system:

characteristic carbon deposits form on the electrodes of the candles (clean them with sandpaper, rinse with gasoline and dry);

the gap between the electrodes is too large or small (it is changed by the method of bending them);

deformed insulators of wiring, spark plugs (should be replaced);

the "Stop" button is shorted to ground;

contacts in the angles of the candles are broken (put them in order);

there are defects in the starter of the ignition system (replace the part).

Perhaps there is a leak in the connections between the carburetor, spark plugs, their heads or cylinders. Check the tightening of the fasteners and the integrity of the gaskets.

Quite often, you can find other types of malfunctions. You definitely need to know them in order to repair the Lifan engine for a walk-behind tractor.

During operation, unstable operation of the walk-behind tractor engine is possible. If you notice suspicious noises or jerks, or similar symptoms, stop the equipment immediately, turn off the engine and let it cool down. Only then can you start diagnostics.

If, in the process of operation, the internal combustion engine independently picks up increased speed, with a high degree of probability, the fastening of the regulator levers and traction could simply weaken. The system will have to be adjusted by yourself.

Are you working at extremely high revs? ICE can jam. Common reasons include:

there is a nadir on the bottom of the connecting rod;

broken connecting rod or oil spray.

It is possible to put a jammed motor in order only after disassembling it and inspecting the main elements. All defective parts must be replaced.

Quite often the carburetor or muffler gets clogged. In the first case, you need to clean all the elements of the part. In the second, remove the accumulated carbon deposits on the inner walls of the mechanism.

Also, a motoblock malfunction often occurs when the carburetor air damper is partially closed. It will be necessary to ensure free play of the damper. If there is a jam, remove it.

In this article, we have considered only some of the main problems associated with the malfunction of the Lifan walk-behind tractors. Many of them can be solved by yourself. The main thing is to know the signs of such problems and how to fix them!

The Chinese company Lifan is a large corporation, uniting many industries: from small-capacity motor vehicles to buses. At the same time, it is also a supplier of engines for a large number of small firms that produce agricultural machinery and small motor vehicles.

According to the general tradition of the Chinese industry, instead of their own developments, copying of any successful model, usually Japanese, is carried out.

The widespread engine is no exception. families 168F, installed on a large number of motoblocks, cultivators, portable generators and motor pumps: the model for its creation was the Honda GX200 engine.

Engine for walk-behind tractor Lifan with a capacity of 6.5 hp, the price of which in various stores ranges from 9 to 21 thousand rubles, depending on the modification, has a classic layout: it is a single-cylinder carburetor engine with a lower camshaft and a rod valve drive (OHV scheme).

Lifan engine

Its cylinder is made in one piece with the engine crankcase, which, despite the theoretical possibility of replacing the cast-iron liner, significantly reduces its maintainability when the CPG is worn out.

The motor has forced air cooling, the performance of which is sufficient when working in hot climates even under heavy loads.

Ignition system - transistor, during operation does not require any adjustments.
The low compression ratio (8.5) of this engine allows it to run on commercial gasoline of the brand AI-92 any quality.

At the same time, the specific fuel consumption of these engines is 395 g / kW * h - i.e. per hour of operation at a rated power of 4 kW (5.4 hp) at 2500 rpm, with the correct carburetor settings, they will consume 1.1 liters of fuel per hour of operation.

The 168F engine family currently includes 7 models with various configuration options and connection dimensions, which have in common the following characteristics:

Cylinder dimension (bore / stroke): 68 × 54 mm;
Working volume: 196 cm³;
Maximum output power: 4.8 kW @ 3600 rpm;
Rated power: 4 kW at 2500 rpm;
Maximum torque: 1.1 N * m at 2500 rpm;
Fuel tank volume: 3.6 l;
Engine oil volume in crankcase: 0.6 l.

The cheapest package with connecting shaft size 19 or 20 mm. Manufacturer's price - 9100 rubles.

Lifan 168F-2

For more information about the operation of the Lifan 168F-2 engine, see the video:

Engine variant equipped with coil lightingcapable of supplying consumers with a power of up to 90 watts. This allows it to be used on a variety of vehicles that require lighting devices: motorized towing vehicles, light swamp vehicles, and so on. Price - 11,600 rubles. Shaft landing diameter - 20 mm.The power unit has tapered shaft exit, 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. Price - 9,500 rubles.This engine has built-in reduction gear with an output shaft diameter of 22 mm and stands 12,100 rubles.The motor is also equipped with reduction gear, but with an automatic centrifugal clutch, and the size of the gearbox output shaft landing is 20 mm. Engine cost: 14,900 rubles.

Engine repair

It should be noted that the manufacturer does not indicate specific wear limits for troubleshooting any engine components, therefore the dimensions given below are indicated by analogy with other four-stroke air-cooled engines:

If you find any play in the bearings, replace them. Also, since the repair dimensions of the parts are not provided, they are replaced with new ones:

Connecting rod: with increased to a noticeable radial backlash on the crankshaft neck;
Crankshaft: in case of seizure on the crankpin;
Carter: with significant (more than 0.1 mm) wear of the cylinder mirror in the largest place;
Piston: with mechanical damage (chips, scuffing due to overheating);
Reciprocating rings: with an increase in the gap in the joint over 0.2 mm, if the cylinder mirror itself does not have a workout reaching the rejection limit, as well as with a noticeable burnout of engine oil.

Before reassembling lubricate all rubbing partsand clean engine oil, and clean the surfaces of the combustion chamber and the piston crown covered with carbon deposits in order to reduce the heat load of these places. Motor assembly is carried out in the reverse order of assembly.To grind grain, a special device is used - the Kolos grain crusher, which is produced at the Rotor plant. Check out this inexpensive and reliable grain crusher here.On the domestic market of agricultural machinery, there are various options for cultivators, not only Russian, but also foreign made. The Mantis cultivator is a reliable technique for decades.A snowmobile sled is a must for comfortable long-distance winter travel. By clicking on the link, learn how to make a sled with your own hands.When installing the camshaft, be sure to align the mark on its gear with the same mark on the crankshaft gear. Image - DIY lifan engine repair

Cylinder head

Pull the cylinder head mounting bolts evenly crosswise in two passes, the final torque should be 24 N * m. Flywheel nut retracts by torque 70 N * m, and the connecting rod bolts - 12 N * m.

After assembling the engine, as well as regularly during operation (every 300 operating hours), it is necessary to adjust the valve clearances. Order of operations:

Set the piston to the top dead center of the compression stroke (since there are no marks on the flywheel, check this with a thin object inserted into the spark plug hole). It is important not to confuse compression TDC with exhaust TDC - valves must be closed!
After loosening the lock nut, rotate the nut in the middle of the rocker arm to adjust the clearance for the corresponding valve, and then secure the lock nut. The gap, set with a flat dipstick, should be 0.15 mm at the inlet valve and 0.2 mm at the outlet.
Having turned the crankshaft exactly two turns, re-check the clearances - their deviation from the established ones may mean a large play of the camshaft in the bearings.

Of the many units with a 6.5 hp Lifan engine, the most common is a walk-behind tractor. Salyut-100.

Salute 100

The production of this light motoblock began in the Soviet Union, according to the then tradition of loading military-industrial complex enterprises with additional production of so-called "consumer goods" and continues to this day at the facilities of the Moscow JSC "Scientific and Production Center Gas Turbine Construction Salyut".

In combination with the Lifan 168F engine, such a walk-behind tractor costs about 30,000 rubles... It has a relatively low weight (76 kg), which, in combination with an average engine power indicator for this class of equipment, makes it plow of little use for plowing without additional weighting.

But for cultivation it is quite good due to the included sectional cutters, which allow changing the working width from 300 to 800 mm, depending on the severity of the soil.

Big advantage motoblock "Salyut-100" over a number of classmates is the use of gear reducermore reliable than chain. The gearbox, which has two forward and one reverse speeds, is additionally equipped with a reduction gear.

The Salyut motor-block does not have a differential, but the narrow wheel track (360 mm) in combination with its low weight does not make it labor-consuming to turn.

Sectional cutters with protective discs;
Expansion sleeves track;
Coulter;
bracket rear hitch;
Tool set;
Spare belt.

Additionally, it can be equipped with a plow, blade, snow blower, metal wheels with developed lugs and other equipment, widely compatible with most domestic motoblocks.

Engine oil for the "Salute" walk-behind tractor with a Lifan engine should only be used low-viscosity (high-temperature viscosity index is not more than 30, in hot conditions - 40).

This is due to the fact that in order to simplify the design of the engine, it does not have an oil pump, and lubrication is carried out by splashing oil with a rotating crankshaft.

Viscous engine oil will result in poor lubrication and increased engine wear, especially in the most loaded pair of sliding friction in the lower end of the connecting rod.

At the same time, since the low level of forcing of this engine does not impose high requirements on the quality of engine oil, you can use the cheapest automobile oils with a viscosity 0W-30, 5W-30 or during long-term operation on heat - 5W-40.

As a rule, oils of this viscosity have a synthetic base, but there are also semi-synthetic and even mineral ones.

At almost the same price, semi-synthetic oil for air-cooled engines is preferable to mineral oil.

It forms less high-temperature deposits that impair the heat transfer from the combustion chamber and the mobility of the piston rings, which is fraught with engine overheating and loss of power.

Also, due to the simplicity of the lubrication system, it is imperative to check the oil level before each start and maintain it at the upper mark, while the engine oil should be changed once a year or every 100 hours of engine operation.

On a new or reconditioned engine, the first oil change takes place after 20 hours.

Thus, the family Lifan 168F engines is an not a bad option when choosing a new walk-behind tractor or the need to replace the power unit with an existing one: they are quite reliable, and thanks to the wide distribution, spare parts for them are easily available.

At the same time, engines of all modifications are easy to repair and maintain and do not require high qualifications for these works.

Moreover, the price of such an engine (9000 rubles in the minimum configuration) is slightly higher than that of unnamed Chinese manufacturers imported by a number of manufacturers under their own brands (Don, Senda, etc.), but noticeably lower than that of the original Honda engine.

Are you here »Homemade mini tractor and everything to it» Engines »The problem with the engine lifan 168f

- most likely the speed regulator has lost its spring. she is small and often flies.
  - - I turned it off, when the sensor was turned on, it was completely deaf.
      
      most likely the speed regulator has lost its spring. she is small and often flies.
      
      Wow. And where does she stand.
      
      Edited by togy (Jun 6, 2011 10:10:15 PM)
      - I have changed the old engine for a lifan 168f. He worked for a year and started to smoke. At the same time, when I was finishing the work, it was stalling constantly (the oil sensor was triggered), I pulled badly. in one word he was worn out. I changed the rings (380 rubles + 0.5 days of work) began to start from a half-barrel, does not smoke, does not stall (I bought SAE-30 oil 5 liters in a tractor store, a little more expensive than 0.6 liters in a motoblock store). Pleased: adjusting the valves (on the exhaust valve there is a cap like a Muscovite one, on the suction valve there is no such cap), it can be disassembled with keys for 10 and 12. Barely - barely unscrewed the connecting rod bolts, I had to turn the small head for 10 with a gas wrench (the key is small about 200mm long)
        Regarding the adjustment, I found in NET the Russian version of the operating instructions, the spare parts catalog and, in principle, the questions disappeared by themselves.
        
        In this material, we will consider typical malfunctions of a walk-behind tractor engine and how to fix them.
        
        Typically, there are two types of engine faults:
        
        1. The engine will not start.
        
        2. The engine does not work satisfactorily (it does not gain power, it runs intermittently, the engine stops).
        
        If the engine does not start, then in search of malfunctions and their further elimination, you should perform the following steps to identify the causes.
        
        - Checking the presence of fuel in the tank (checking the fuel system)
        
        - Checking the carburetor air damper (when starting a cold engine, the damper must be closed)
        
        - Checking the flow of fuel to the carburetor.
        
        - If there is no fuel entering the cylinder, a dry plug is indicated. Check the presence of fuel in the fuel tank, fuel flow to the carburetor by removing the fuel hose from the inlet fitting. For the K45 carburetor, press the sinker until the fuel leaks through the drain hole.
        
        - If fuel does not flow to the carburetor, unscrew the fuel cock, disassemble it and clean the filter from dirt.
        
        - When fuel enters the carburetor, but there is no fuel supply to the cylinder, check the operation of the fuel valve and the cleanliness of the jets.
        
        - To check the KMB-5 carburetor, remove it from the engine, drain the gasoline from the float chamber, then supply air through the fuel inlet in the operating position of the carburetor. The air should be easily blown through.
        
        - Repeat the purge with the carburetor turned 180 degrees, in this position the air supply should stop. If the result is the same as described, the fuel valve is working properly.
        
        - The fuel level in the float chamber is regulated by the float tongue, the normal fuel level should be 30-35mm.
        
        - After all actions with the carburetor and installing it back, the carburetor should be adjusted.
        
        - It so happens that the engine does not start from excess fuel, this is evidenced by a wet plug. Dry the cylinder and “bleed” the engine with the plug turned out, before that, turn off the fuel supply.
        
        - If the plug is dirty with deposits, clean it and check the gap between the electrodes, usually the correct gap is 0.8mm. Next, you should check for the presence of a spark, if there is no spark, then there may be a malfunction in the electrical circuit or a large gap between the ignition coil and the magnetic circuit.
        
        If the engine starts, but does not develop the required power, runs intermittently, stalls, etc., the reasons for this may be the following malfunctions:
        
        - The air filter is dirty, as a result of which there is insufficient air flow to the carburetor.
        
        - Defective ignition system. You should check it, as well as check the candle, the gaps between the electrodes, etc.
        
        - Clogged muffler with combustion products. The muffler should be disassembled for cleaning.
        
        - Dirty carburetor and incorrect setting.
        
        - Low power may be due to wear of the cylinder-piston group. The compression should be 8 atm. You can check the compression by attaching a compression gauge to the spark plug hole, turning the engine shaft with a starter.
        
        Read also, information on how to make a trailer for a walk-behind tractor with your own hands.
        
        If the engine of the walk-behind tractor does not turn off, first of all it is necessary to pay attention to the operation of the shutdown button. It is necessary to disassemble, check and, if necessary, replace or clean the contacts.
        
        Video (click to play).