DIY ural walk-behind tractor repair

In this thread, we will disassemble the malfunctions of motoblocks and cultivators of all brands, Salute. Neva, Bison, etc., and their removal and repair. Most of the problems are typical for all types of motoblocks, their engines and other components.

It often happens that a previously serviceable walk-behind tractor that has served for several years suddenly loses power.

- If the power has dropped after long-term storage, it is possible that the walk-behind tractor was stored with a wet carburetor and fuel system, which led to deposits. In this case, you can start the engine and let it work, often, after these actions, the power is restored. If you have skills, you can disassemble and clean, if there are no skills, it is better to contact the service.

- The carburetor may be clogged... Clean

- Clogged benzo hose... It needs to be purged.

- Possible loss of serviceability of the cuff cuff... Remove the casing and gearbox cover, inspect the oil seal.

- Carbon deposits on the cylinder, muffler... Clean up.

- Clogged air filter... Clean up.

- No compression... Change piston rings, cylinder, piston.

- If the engine is on a slope, you need to put it horizontally.

- The fuel may not be supplied to the carburetor... It is necessary to disassemble and purge the fuel system with air.

- The filter may be clogged... The filter needs to be replaced or cleaned.

- The outlet in the gas tank cap may be clogged... Needs to be cleaned.

- Maybe it's the candle... It is necessary to check the connection of the wires, the engine stop buttons, unscrew the spark plug and clean. Replace if necessary.

- Possible failure of magneto... Replace.

- The engine may not yet warm up... Need to warm up

- Candle contamination is possible... It is necessary to clean the candle by removing carbon deposits.

- The end of the wire does not fit snugly against the candle... Press the end of the wire firmly against the candle.

- Possibly too large a clearance of the gearbox cover... Make a gap of 0.2-0.5

White smoke is pouring out of the walk-behind tractor, it starts to work in a "choke".

- Possibly low-quality gasoline is poured or, this is due to a strong tilt of the walk-behind tractor. The oil runs out of the crankcase at a slope, and until it burns out, the smoke comes to the valve like from a stove. Also read the material "Repair of a walk-behind tractor"

- Can squeal if there is a lot of grease on the balls. You need to clean the balls and the places in the ratchet where they are inserted.

The cultivator made several claps, the revolutions began to "float"

- Most likely, the power supply system does not cope, or the fuel level in the tank is low, the axis of the float may be skewed and debris may have got under the needle valves, you need to remove everything and check the air filter, jets.

The material will be updated, we are waiting for comments with questions, stories about identifying a particular malfunction and how to fix it. Also, see the answers to questions about a particular model of a walk-behind tractor on its description page.

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.

Under 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.

Motoblock Ural was produced from 1990 to 1998 by the defense enterprise TsMPO, located on the territory of Bashkiria. The production was discontinued due to the development of the modernized Agros model. Products under the Ural brand were among the most popular brands - over 8 years of production, more than 100 thousand copies were produced.

According to the instruction manual for the Ural walk-behind tractor, the product consists of a frame made of a steel profile. A power unit, a clutch mechanism and an additional 2-speed gearbox are installed on the frame. The power unit is mounted via rubber shock absorbers to reduce vibration on the controls.

2 wheels are used for movement. Solid rubber tires with a diameter of 430 mm and a width of 110 mm are used on the walk-behind tractor. Fixed track width - 540 mm. The walk-behind tractor is controlled by handles fixed to the frame. Using the handles, you can turn, change the engine speed and change speeds. The steering can be adjusted to suit the height of the operator. A bar with holes is used for adjustment.

• length - 1880 mm;
• width - 690 mm;
• height - 1280 mm.

A pin is installed on the front of the frame, which is used to install attachments. The pin is housed in a steel body bolted to the cross member. In the body of the pin there are 2 holes through which the attachments are fixed. On the rear cross member there is a bracket for attaching trailed implements.

The engine installed on the walk-behind tractor needs regular maintenance with partial or complete disassembly. After 250 hours of operation, lapping and valve adjustments are required. There are marks on the gears for setting the valve timing. The clearance between the tappets and valves is adjusted using a special screw located at the end of the tappet.

The manufacturer allows a variation in the length and height of products within 50 mm, in width - within 20 mm. The weight of the equipped device is 120 kg, the mass of the towed trailer is 350 kg. The maximum travel speed is 11.5 km / h. For the fastest possible movement, a combination of the highest gear in the engine and higher speed in the additional gearbox is used.

The engine of the Ural UMZ-5V walk-behind tractor is a 4-stroke 1-cylinder petrol unit with a volume of 475 cm³. The motor was originally designed for use on self-propelled agricultural machinery and stationary installations. The power unit develops a power of 4.5 liters. With. at 2000 rpm. The plant allows for a short-term increase in power up to 5 liters. With.by increasing the speed.

Long-term operation at increased power is not allowed, as it leads to overheating.

The engine is equipped with an air-cooled system. A fan is used to cool the engine and blows air into a shroud around the cylinder and head. When operating the walk-behind tractor, it is required to regularly inspect and clean the cooling fins from dust and oil. Accumulated dust impairs heat transfer and causes local overheating, which leads to increased engine wear.

The motor is equipped with an automatic speed governor. For this, a centrifugal mechanism is used, which does not allow a rotational speed of more than 2350 rpm. When the speed is exceeded, the throttle valve is displaced, which leads to a drop in the speed. The engine manufacturer prohibits self-adjusting the speed limiter and its use for speed control.

The gas distribution system consists of 2 bottom valves. Because of this, the motor has a low compression ratio of 6 units. The engine uses automobile gasoline A-76 (A-80) as fuel. The fuel supply is located in a tank located above the engine carburetor, the fluid supply is gravity. The fuel supply in the tank is 6 liters, which provides an operating time of up to 4-4.5 hours. The operating time depends on the condition of the engine and the nature of the tasks being performed.

The engine of the Ural walk-behind tractor is equipped with a 2-speed gearbox with crawler gears. The first speed reduces the rotational speed by 6 times and is used to perform work with a high coefficient of resistance (for example, plowing virgin soil). The second speed reduces the revolutions by 2.91 times and is used to operate the product with a trailer or when plowing soft soil. Switching the speeds of the UMB-K Ural walk-behind tractor according to the instructions is performed on the idle engine.

The engine is started by a cord that is wound around the flywheel. Before starting, it is required to set the crankshaft to the end of compression position. The engine can be started in 1 or 2 gears of the geared motor.

The output shaft of the engine is equipped with a 2-strand pulley designed to transmit torque to the auxiliary gearbox and to drive the attachment. On the fan side, there is a second pulley used to drive attachments that require an increased speed of rotation of the working parts. The clutch mechanism consists of belts and tension rollers.

Transmission oil in a volume of 1.5 liters is filled into the transmission crankcase of a walk-behind tractor with an UMZ-5V engine, according to the repair instructions. The filling of the substance is carried out through a hole closed with a plastic stopper.

The standard set of attachments for the walk-behind tractor included a cultivator. For the transportation of goods weighing up to 350 kg, a 2-wheel TOP-350 / 350M trolley was used. When using a single-body plow, an adapter is required to be attached to the frame. The use of the plow is allowed in conjunction with metal wheels equipped with grousers. A mounted potato digger is used in conjunction with the plow.

Small batches of motoblocks were equipped with a ZiD-4.5 power unit. By design, the motor does not differ much from the UMZ-5V. A pulley and sprocket are located on the crankshaft for driving the chain. The pulley is located on the flywheel side, the chain drive on the gearbox side. The chain drive is used to drive stationary installations. The engine is lubricated by spraying, oil is supplied by a plunger pump from a sump that holds 1.5 liters of fluid.

A belt drive is used to transfer torque from the engine to the transmission. The belt for the walk-behind tractor has a size of 1120 * 17 * 11 mm. A 2-speed transmission is used on the walk-behind tractor, the device and control of which are similar to machines with a UMZ-5V engine.The reducer has 2 speeds, decreasing the rotational speed by 17 and 7 times, respectively. Gear shifting is done with a handle. Before starting to operate the walk-behind tractor, it is required to check the level and add gear oil to the gearbox. The nominal capacity of the crankcase is 1.5 liters.

The engine ignition system includes a magneto that provides a constant ignition timing. With wear, the angle changes, which leads to unstable ignition. To adjust the ignition of the walk-behind tractor, it is necessary to control the moment when the breaker contacts open and the maximum gap between them. The check is carried out with the flywheel removed by aligning the notch on the crankshaft with the notch on the base of the magneto armature.

The power system includes a K16N or ZiD-12 carburetor and a fuel tank that can hold 8 liters of gasoline. Adjusting the carburetor of the walk-behind tractor allows you to ensure uniform engine operation and the fuel consumption declared by the plant. Adjustment is made with the engine warm by turning the idle screw and throttle stop screw. This adjusts the minimum idle speed.

Many owners of Ural motoblocks lack the power of a standard power unit. Instead, Chinese engines or other imported motors are often used. The Chinese engine is installed on a standard frame through additional cross members. The cross members are attached to the frame by welding or bolts. Imported power units have an increased crankshaft speed, therefore, the use of homemade pulleys in the clutch is required.

The increased power of the power unit expands the possibilities for DIY modification. The equipment is capable of working in winter with an installed rotary snow blower.

Based on reviews of the Ural motoblocks model range, a number of advantages can be distinguished:

• the weight of the product is 120 kg, so there is no need to exert additional physical influence on the control handles during operation;
• the possibility of alteration and modernization;
• the engine for the Ural walk-behind tractor with a gearbox has a long resource;
• effective air cleaner that does not require replacement of filter elements;
• simplicity of design and the possibility of self-repair.

The owners point out the disadvantages:

• oil leaks at the joints of engine and gearbox parts;
• the need to check the oil level;
• increased fuel and engine oil consumption due to the design of the gas distribution mechanism;
• The walk-behind tractor is not suitable for long trips with a trailer due to its low speed.

Ural products with ZiD or UMP engines are estimated by their owners at 9 to 15 thousand rubles. Motoblocks with Chinese motors on sale are rare, their cost is in the range of 14-20 thousand rubles.

The motoblock is used for plowing a personal plot. During the work there were problems with the ignition. After installing the coil from the contact ignition of a VAZ car, the situation has improved. Instead of a magneto, a battery from a computer uninterruptible power supply unit is used. The ignition works stably throughout the entire rev range. The engine is stopped by switching off the power supply from the battery.