✅ How to disassemble the gearbox on the Neva mb 2 walk-behind tractor

Operation and maintenance of Neva-MB-2

To avoid failures in the operation of the MB-1 and MB-2K mini tractors, you should follow all the recommendations for the operation and maintenance of equipment prescribed in the instructions:

You need to tune the engine. To do this, you will need to study the device of this part, choose the right oil for servicing the motor, spark plugs and fuel.
Set up and adjust the gearbox and transmission. The serviceability of these parts must be checked every day before starting work.
Install accessories only in accordance with the user manual.
Follow the maintenance schedule (points 1 and 2) and seasonal maintenance (before the summer and winter periods).

Strengths and weaknesses of the Neva walk-behind tractor

With regard to the Neva motor tool, a lot of good and not very good reviews and opinions were expressed about the operation of the tool. But it is worth recognizing the main thing: the Neva is one of the few domestic-made walk-behind tractors with great potential. Owner reviews say that the machine can easily pull the milling of a strip of earth, 180-190 mm wide, of course, with proper care and use.

The vast majority of Neva users can be divided into two categories:

Motoblock series "Neva 2"

For the price, the walk-behind tractor of the second series can be attributed to the most popular models of the Neva. The price of a unit with a Subarovsky engine will be at least 47 thousand rubles, which is almost 10 thousand more expensive for an equally interesting MD-1 block, which has the same engine of 6 horsepower. The second series of walk-behind tractors is the lightest, the weight of the walk-behind tractor is only 75 kg. For one employee, this is a lot if you have to load and unload equipment in the trunk. Only the Neva MB Compact model with a weight of 70 kg is lighter.

"Neva 2" can be equipped with an American Briggs & Stratton engine, a Honda engine with a power of 5 or 6 hp, or a 6 horsepower Subaru EX-17D engine. There is no fundamental difference, except that the "Subarov" motor starts very poorly at low air temperatures.

The width of the strip can be 120 cm, but this size is only achieved by installing two extensions with cutters on each side of the gearbox. The milling depth is up to 20 cm, but the work parameter largely depends on the width of the grip and your own physical strength, since in the process of work you have to “help” the walk-behind tractor, leveling and loading it with your hands.

Motoblock "Neva" with the engine "Briggs & Stratton" is recognized as the most economical and reliable in operation, although it is more heavy than the "Japanese". With proper organization of work 5 l. there was enough fuel for cultivating 6 acres of medium-heavy soil.

If you wish, you can learn a lot of interesting things about the operation of the unit from the video:

Motoblocks of the MB-1 and MB-3 series

It is worth mentioning separately the Neva walk-behind tractors of the first and third series.

The parameters of the Neva MB-1 are only slightly inferior to those of the second series, but the manufacturer considered it necessary to create and offer gardeners and gardeners a car with a different gearbox. Instead of the standard gear-chain version with oil sump lubrication, the MD-1 has a specialized RS950 classification gearbox under its own name "Multiagro".

The reducer has the main feature - opening and blocking of one of the two shafts at the output of the reducer with the ability to redirect all torque and maximum power to the remaining unblocked shaft. This method quite seriously simplifies the work on virgin lands, “clumsy” and dense salt marshes with an abundance of roots. The width and depth of tillage correspond to the motor units of the second series.

The model of the MB-1 walk-behind tractor is equipped with the "American" Briggs & Stratton, which has a large torque at low revs. Unlike the "Japanese", the American motor starts well and keeps the operating speed in any mode, although this design is heavier in weight, up to 86 kg.

Blocks "MB-3" can be considered as a modification of the model "Neva MB 2". It significantly reduces the weight and height of the center of gravity of the unit, which reduces the load on the hands.

In the MB-3 motoblock, some design refinement can be noted:

There was protection of the gearbox from roots and plant residues, the walk-behind tractor became more compact and squat;
The weight of the unit has decreased by 5 kg, largely due to the use of hollow profiles and pipes of the frame and drives;
The quality of control knobs, cables and locking handles has been significantly improved, which radically simplifies the control of the motor operation mode.

However, in the design of the "Neva" there are still some shortcomings with adjusting the height of the control stick and an extremely inconvenient way to switch speeds by transferring belts to an additional pair of pulleys.

As in the second model, the same engines are used in the MB-3 as previously - Briggs & Stratton and Subaru, so the model has clearly not lost power. The convenience and benefits of the "MB-3 Neva" can be assessed by the video:

Heavy models of the MB-23 motoblock

Heavy motoblocks "Neva" are equipped with engines "Briggs & Stratton" and "Subaru", "Honda" with a volume of 300 cubes and power up to 10 hp. The power of such a unit allows you to process the standard 6 acres twice as fast, but now instead of 5 liters you will need to spend up to 10 liters of fuel.

The Neva walk-behind tractor turned out to be heavier, its weight was 105 kg, but now the width of the cultivated strip has increased to 180 cm, with a loosening depth of 230-240 mm. Not everyone can work with such a colossus, even a relatively physically strong person. But such a walk-behind tractor can fully replace a mini tractor, if supplemented with a coupling device and a trailer. Theoretically, you can carry up to 400 kg of cargo.

An interesting solution is the Neva variant with the MD 23SD diesel subarik. By using a motor with a very high torque, it was possible to obtain a very high quality of soil milling with a slight increase in weight. According to the owners, the diesel version has a huge rotational power and has proven itself very well in cultivation, planting seeds and transporting goods on very bad roads.

Engine oil change

The procedure for changing the oil in the engine:

Park the vehicle on a level surface.
Let the engine cool down. This will help to measure the level of filled oil.
Clean the area around the dipstick plug located on the left side of the engine.
Fill in the oil liquid to the maximum mark (recommended oil - TAD-17I, TAP-15V).
To determine the level to which the fuel fluid was filled, you need to use dipsticks. To do this, you need to take a dry dipstick plug and insert it into the oil filler port. From the remaining trace, you can determine to what level the liquid was filled.
With an excess of oil fluid, a leak begins, which can lead to malfunctions in the walk-behind tractor.

First start-up and run-in

Running-in is necessary so that all parts can rub in. After working for a short period of time at a minimum level of load, in the future the walk-behind tractor will fail less often.

Rules:

The break-in process must not be less than the time specified in the operating instructions.
Loads should be small. For example, if the technical specifications indicate that the maximum tillage depth is 50 cm, then during the first start and break-in it is recommended to limit it to 30 cm.
Before running in, it is necessary to fill the engine with oil.

Break-in order:

Fill up the fuel tank.
Run the unit at medium speed.
Within 60 minutes it is necessary to check the operation of all gears.
Perform a small amount of work on cultivation, plowing the soil and transporting small loads.

Main malfunctions

The reason for the repair of the Neva MB-2 walk-behind tractor can be:

improperly adjusted valve belt;
gearbox failure;
gearbox seals;
incorrect setting of the carburetor system;
not exposed ignition;
spark plug problems.

Adjustment and dimensions of the belt

The V-belt on the walk-behind tractor helps the unit move forward and backward. When the drive belt comes off, the equipment ceases to function correctly.

Replacing the gearbox seals

The reason for the failure of the gearbox may be improperly functioning oil seals. Therefore, the repair of the Neva walk-behind tractor gearbox may include the following steps:

Dismantling of cutters from the shaft.
Cleaning the shaft and cover from dirt and oil residues. Remove all screws from the cover and clean them.
Replace the old spare part with a new one and wipe the entire mechanism dry.
Put the cover back in place and fix it with screws.

In some cases, it is necessary to disassemble the gearbox:

Remove the head from the gear shift knob.
Remove the bushing and spring from the shaft.
Remove all screws and tightening bolts.
Using a thin screwdriver or knife, remove the right half of this part.
Removed parts must be washed, and defective parts must be replaced.
The gearbox is assembled in the reverse order.

Do-it-yourself repair of the gearbox of the Neva MB-2 walk-behind tractor

The Neva MB-2 walk-behind tractor gearbox has a fairly simple design, and its repair usually does not require certain skills. Pay attention to the following signs that indicate a breakdown of the node:

oil leakage on the output shaft of the gearbox;
gears stopped changing;
lack of kinematic connection;
the transmission chain began to jam.

If one of the listed problems occurs, it is necessary to disassemble and inspect the mechanisms of the device.

If oil leakage was noticed, this indicates wear of the cuff or excess lubricant filled in. Excess oil will be sufficient to drain, and in case of wear of the gasket part, it will need to be replaced.
In the event of a chain jamming, it will be necessary to install a new one, since a worn or broken chain cannot be repaired (you can try to weld the links, but in this form the part will not last long).
If, during a visual inspection, it turned out that the main transmission element is intact, but there is a slip or there is no kinematic connection, you should pay attention to the stars. One or more of them may crack or break. Replacing them will help fix the problem.
When there are difficulties in shifting gears, the cracker of the shift shaft of the motor-block gearbox is probably destroyed, or the thread of the handle is cut off. In this situation, it will also help to replace parts with new ones, or those removed for disassembly from a similar gearbox.

Before you start disassembling the assembly yourself, study the detailed video instructions from experienced craftsmen, as any repair mistake made due to inexperience can lead to an even bigger problem and the need for expensive repairs.

Carburetor setting

Before adjusting the carburetor, it is necessary to adjust the centrifugal regulator, according to the user's instructions.

Setting order:

Tighten the idle and full throttle bolts to the maximum, and then back them out 1.5 turns.
Install a butterfly damper so that there is a gap of appropriate parameters between the base and the duct.
Try to start the engine. If it starts, you need to wait until it warms up.
Set the control handle to minimum speed.
Run the minimum idle speed with the throttle screw.
Set the speed to maximum using the idle screw.
Repeat the last 2 steps until the motor runs smoothly.
Set the control stick to the gas.

Adjustment of valves

The valves on the Neva walk-behind tractor are adjusted as follows:

Install the unit on a flat surface.
Start the engine and then let it cool down.
Take off the casing.
Remove the cover from the valves to provide access to the parts under it.
Unscrew the locknut.
Perform the adjustment. It is necessary to loosen the nuts, insert the probe, adjust the valves.
Screw the valve nut back into place.
A razor blade (no more than 0.2 mm thick) is inserted into the resulting gap. It must pass freely between the piston part and the walk-behind tractor valves.
Screw all parts back.

The size of the resulting gap can be checked with a feeler gauge, which should pass under the valve if the cut is made correctly.

Checking and adjusting the clutch

Clutch check:

When the clutch lever is in the "off" position, the cable must be loosened. The tension roller moves to the lower position and comes into contact with the drive type belt.
When the handle is in the “On” position, the cable tightens the roller, and the lower part of the belt is pressed tightly against it. The small pulley transmits the momentum to the large pulley, which results in power transmission.

Adjustment procedure:

If it knocks out 2nd gear with the clutch handle engaged. It must be moved to the correct position. To do this, it is necessary to place the V-belts in parallel on 2 sides of the motor pulley.
If 2nd gear flies when the clutch handle is off. It is necessary to constantly control the position of the V-belts, they must be parallel to each other.

How to set the ignition

Before carrying out the procedure, it is recommended to make sure that the design can cause a spark that will ignite the fuel in the internal combustion chamber.

The procedure for adjusting the ignition of the walk-behind tractor:

Turn the crankshaft so that the marks made on the pulley and the gas equipment of the unit coincide.
The slider, which is responsible for the distribution of gas flows, must be directed to the high-voltage wire of the cylindrical part.
Loosen the nut and remove the high voltage wire from the cover of this system.
Place the contacts at a distance of 0.5 cm from the equipment.
Turn ignition.
Turn the mechanical structure in the opposite direction.
After the appearance of a spark, you need to quickly tighten the screw.

Faults with candles

To begin with, it is recommended to make sure that the candle is working. For this you need:

Unscrew the candle element.
Clean the electrodes.
Get rid of soot.
Turn the crankshaft to a position where the marks on the pulley and the gas device coincide.
Direct the slider to the high voltage surface of the cylinder.
Loosen the screw and remove the wire.
Turn the ignition key. If there is no spark, then the spark plugs are faulty and should be replaced. Before installing a new element, make sure that there is no sealing washer from the previous part in the cylinder head.

It is also necessary to check the parameters of the gap between the electrodes of the candles:

Candle part model	Gap
A11R	0.5÷0.6 mm, size - 2.8 cm
NR17C	0.5÷0.6 mm, size - 2.8 cm
WR8AC	0.5÷0.6 mm, size - 2.8 cm

Why it doesn’t start, shoots, smokes, and what to do about it

Do-it-yourself engine repair is recommended only after the warranty period has expired.

If the engine does not start, the reason may be as follows:

There is no spark. In this case, it is recommended to pull out the candle element and insert it into a special candlestick, and put the body on the cylinder. After that, you need to start the engine. If a spark does not appear, it is recommended to replace the candle.
Fuel does not reach the engine. It is necessary to inspect and blow out the hose that connects the carburetor and the faucet. If necessary, you can disassemble the carburetor and rinse it from the inside with A-95 gasoline.

If the cultivator smokes at idle, you need:

Inspect and clean the air filter.
Check oil level. Drain excess if necessary.

If the engine fires, then the reason for this may be the tension of the working spring. In case of malfunction, it should be adjusted.

How to install a generator

In order to install an electric generator, you must do the following:

The generator has 4 wires, 2 of which are blue. You need to connect an energy converter to these 2 wires.
The black wire should be connected to the motor.
Connect the remaining red wire to the parts responsible for external lighting and sound signal.

The generator generates electrical energy, which is supplied to the rectifier. During the start of the motor, the adjusted belt transmits the torque to the rotary part of the unit. In the electric unit, a voltage is generated, from which the battery of the walk-behind tractor works.

The power of the selected generator must not exceed 220 V. It is recommended to choose a spare part whose power will correspond to the expected load.

Video: Adjusting the Clutch of the Neva Motoblock

Carbon settings

Before adjusting the carburetor, it is necessary to adjust the centrifugal governor in accordance with the owner's manual.

Tighten the small and full throttle valves to the maximum value, and then unscrew them 1.5 turns.
Install the butterfly valve so that there is a gap between the base and the channel between the parameters.
Try to start the engine. If it is rolled up, you need to wait until it warms up.
Set the control knob to minimum speed.
Run the minimum idle speed with the throttle screw.
Set the maximum speed with the idle screw.
Repeat the last 2 steps until the engine starts to run normally.
Set the control stick to gas.

Valve adjustment

The valves on the Neva walk-behind tractor are adjusted as follows:

Place the device on a flat surface.
They start the engine and then let it cool down.
Remove the cover.
Remove the cover from the valves to gain access to the parts underneath.
Loosen the locknut.
Make adjustments. You need to unscrew the nuts, insert the probe, adjust the valve.
Screw the valve nut back into place.
A razor blade (less than 0.2 mm thick) is inserted into the gap. It must pass freely between the piston part and the walk-behind tractor valves.
Screw all parts back.

The size of the resulting gap can be checked with a probe, which should pass under the valve if the incision is made correctly.

Check and adjust clutch

When the clutch lever is in the disengaged position, the cable must be loosened. The tension roller moves to the lower position and comes into contact with the drive belt.
When the handle is in the “On” position, the cable pulls the roller and the lower part of the belt is pressed tightly against it. The small type pulley transmits momentum to the large pulley, so that power is transmitted.

If he hits second gear with the clutch lever engaged. It must be moved to the correct position. To do this, put V-belts on 2 sides of the motor pulley in parallel.
If 2nd gear is out, the clutch lever is disengaged. It is necessary to constantly monitor the position of the V-belts, they must be parallel to each other.

How to set the ignition

Before carrying out the procedure, it is recommended to make sure that the design can cause a spark that ignites the fuel in the internal combustion chamber.

The procedure for regulating the ignition of a walk-behind tractor:

Turn the crankshaft so that the marks on the pulley and gas equipment match.
The slider responsible for the distribution of gas flows must be directed to the high-voltage wire of the cylindrical part.
Unscrew the nut and remove the high voltage wire from the cover of this system.
Place the contacts at a distance of 0.5 cm from the equipment.
Turn on the ignition.
Rotate the mechanical structure in the opposite direction.
After a spark appears, quickly tighten the screw.

Malfunctions with spark plugs

To begin with, it is recommended to make sure that the candles are in good condition. For this you need:

Unscrew the spark plug element.
Clean the electrodes.
Get rid of soot.
Rotate the crankshaft to the position where the signs of the pulley and the gas device match.
Move the slider to the surface of the high tension cylinder.
Loosen the screw and remove the wire.
Turn the ignition key. If there is no spark, the spark plugs are faulty and should be replaced. Before installing a new element, make sure that there is no sealing washer from the previous part in the cylinder head.

READ LBM Sparky Variable Speed

It is also necessary to check the parameters of the gap between the electrodes of the spark plugs:

Model of candlesticks	gap
A11P	0.5 ÷ 0.6 mm, size. 2.8 cm
NR17C	0.5 ÷ 0.6 mm, size. 2.8 cm
Wr8ac	0.5 ÷ 0.6 mm, size. 2.8 cm

Why not start, shoot, not smoke and what to do about it?

Self-repair of the engine is recommended only after the warranty period.

If the engine does not start, the reason may be as follows:

There are no sparks. In this case, it is recommended to remove the spark plug element and insert it into a special candle holder, as well as put the housing on the cylinder. Then you need to start the engine. If a spark does not appear, it is recommended to replace the spark plug.
Fuel does not enter the engine. You need to inspect and clean the hose connecting the carburetor and valve. If necessary, you can disassemble the carburetor and rinse it from the inside with A-95 gasoline.

If the cultivator is smoking at idle, you need to:

Inspect and clean the air filter.
Check the oil level. Drain excess if necessary.

If the engine fires, the cause may be the tension of the mainspring. In the event of a malfunction, it should be adjusted.

How to install a generator

In order to install an electric generator, you must do the following:

The generator has 4 wires, 2 of which are blue. The energy converter must be connected to these two wires.
The black wire must be connected to the motor.
Connect the remaining red wire to the parts responsible for external lighting and sound.

The generator generates electrical energy, which is fed to the rectifier. When the engine starts, the adjusted belt transmits torque to the rotor of the unit. The voltage from which the walk-behind tractor battery operates is generated in the electrical unit.

The power of the selected alternator must not exceed 220 V. It is recommended to choose a spare part whose power will correspond to the expected load.

Helpful Hints

The gearbox has 5 positions. When the user presses the shift lever, the fork disengages the clutch from the engaged position. When the user throws the handle, it returns to its original position.

In order for this mechanism to function properly, it is necessary not to make sudden movements and clean all parts from contamination in time.

The gearbox is responsible for transmitting torque from the engine to the wheels and accessories. In order to avoid failures during operation, it is necessary to carry out maintenance of the motor on time.

To lubricate the bearings in the housing, it is recommended to choose Ciatim-201, and wash them with A-92 or A-95 gasoline.

What malfunctions of the Neva walk-behind tractor do you most often encounter? Can you do the repairs yourself?

Adjusting the clutch belt on the Neva MB 2 walk-behind tractor

There is a belt coming off the pulley, slipping, replacing after a break. The instruction prescribes the dismantling of the compensation roller. Possible option:

We loosen the bolt fastening of the engine to the frame.
Pull the motor towards you - tension, reverse movement - weakening.
By pressing, we determine the amount of deflection. Optimal - 10 mm.

Tensioning the belt of the Neva MB-2 walk-behind tractor