Motoblocks are rather compact devices focused on carrying out various agricultural operations on relatively small areas, transporting small loads and other tasks. This article describes the Belarus MTZ-12 motor-block, the features of its design and operation.
This model of the walk-behind tractor is a rather heavy and powerful wheeled construction, due to the features of which the MTZ-12 is quite easy to upgrade to a mini-tractor.
Table of technical characteristics of the MTZ-12 motoblock.
4-stroke carburetor SK-12
Engine displacement, l
Type of engine cooling
Engine power, l with.
Number of gears
4 front and 2 rear
friction control - manual
Speed: when moving forward, km / h
when driving back, km / h
Fuel consumption, g / kW * h
Tire dimensions, cm
Overall dimensions, cm
Total weight kg
Depth of cultivation, cm
Shaft rotation speed, vol. / min
This device is designed for diverse processing of large land plots. If the site does not differ in impressive area, then it is more advisable to choose a unit of lower power.
It should be noted that the height of the control knob, which the owners of this model often complain about, can be adjusted. In addition, it can be rotated to the right and left to 15 degrees.
Also, additional equipment can be attached to this device, which will allow to increase the list of possible operations carried out by the walk-behind tractor. When using additional equipment, you can get the following solutions:
- mounted mower;
- foot cultivator;
- three-wheeled semitrailer designed for cargo weighing up to 500 kg.
The maximum total mass of attached additional mechanisms is 30 kg. The model’s disadvantages include the outdated appearance, the configuration of the structure (when compared with foreign similar devices, for example, Weima, which has a capacity of 13 hp) and insufficient ergonomics.
This model of motoblock is easy to use - this is facilitated by the simplicity of its structure. The instruction manual comes complete with the unit, here are just some tips on the proper preparation and use of the mechanism.
- Before using it for its intended purpose, it is necessary to run the machine idle at the lowest power to facilitate the grinding of the transmission and engine parts.
- Do not forget about the regular lubrication of the nodes of the mechanism.
- The power take-off shaft must be turned on only after reducing the engine speed and turning off the clutch, otherwise there is a risk of the balls flying out and breaking the box.
- Attachments must be attached carefully and securely. Also, do not forget about the tight installation of the king pin.
- Before using the walk-behind tractor with a trailer, carefully check the serviceability of the brakes of the mechanism.
- When operating on extremely heavy and humid earthen areas, it is better to change wheels with pneumatic tires for lugs - discs with special plates, instead of tires.
For the correct and long-term use of MTZ-12, you need to adjust the clutch. If the motoblock twitches when you press the clutch, then it is worth tightening the adjustment screw. In the case when with the released clutch the walk-behind tractor moves slower than it should, it is necessary to slightly loosen the screw.
During operation, various problems and breakdowns may occur. Many of them can be prevented if you follow the manufacturer's instructions for using the unit.
If you regularly use the walk-behind tractor, and also when the loads on it are too high, there is a high probability of a problem such as a decrease in the clearance between the valves. This is manifested in interruptions in the operation of the unit and a decrease in the power of the device. In other words, when the inter-valve gaps increase, extraneous noise appears in the engine. The valves do not open fully, and the fuel supply to the cylinders is disrupted.
If there is a suspicion that such a situation arose, then it is necessary to perform valve adjustment.
- To do this, remove the casing from the flywheel and pre-prepare a thin blade with a thickness of 0.1-0.15 mm - this is the normal value of the inter-valve gaps.
- The nut should be loosened a little. Then you need to insert the prepared blade and lightly tighten the nut.
- After that it is necessary to turn the flywheel - the valve should move easily, but without gaps.
- If necessary, it is better to re-adjust.
If the stroke of the walk-behind tractor has become uneven, then it is worth checking the tire pressure - most often the cause of such a malfunction is the difference in tire fullness. If the unit with the attached additional equipment has become difficult to control and excessive vibration is felt, you need to check the correctness of the attachment of the mounted mechanisms. Oil leaks if the gaskets and seals are ineffective - they should be replaced.
If the box is very hot, you need to check the condition of the bearings. In the event of a malfunction of the clutch, the cause may be deformation of the friction discs, oil contamination, or breakage (loosening) of the cable. Engine malfunction is expressed in reduced power or a complete start failure.
If the engine does not start, then you need to check the state of the ignition system (to correct the situation, you need to test the contact of the candles with the magneto), is there fuel in the tank, how is the fuel transferred to the carburetor, how does its shutter function.
A decrease in power may have the following reasons:
- clogged ventilation filter;
- poor quality of the fuel mixture;
- exhaust system pollution;
- reduction of compression in the cylinder block.
The cause of the first three malfunctions is an irregular inspection and untimely preventive procedures, but the fourth problem is not so simple - it shows that the cylinder is worn out and repair is required, possibly even with a complete rotor replacement.
A malfunction such as a malfunctioning transmission is also often observed. The reason is the deterioration of the discs and the weakening of the spring elements. To eliminate such breakdowns, you need to replace worn components with new parts.
See how to make a mini tractor from MTZ-12 walk-behind tractor in the next video.