Tutaev engine DIY repair

New, now I have a manual for disassembling the TMZ engine. 🙂 ———————————————- → Disassembly (Part 2).

At your request, I am posting a video tutorial on assembling the TMZ engine. 🙂 ——————————————- → Part.

service center # TIMER # KIROVETS.

At your request, I am posting a video tutorial on assembling the TMZ engine. 🙂 ——————————————- → Part.

service center # TIMER # KIROVETS. The bridegroom of the new K744p3 and the continuation of the sowing season.

Replacing the podipnik and the oil seal of the kolin-shaft.

defective motor. calculated the losses. made a list of spare parts. we will order, we will receive the parcel, we will waste the CPG.

New, now I have a manual for disassembling the TMZ engine. 🙂 ———————————————- → Disassembly (Part 1).

READ THE FULL COMMENT !! LINK . Assembling the T-200 engine in the early 60s (Ant motor scooter) How to get around.

Tutaevsky Motor Plant. Engine overhaul k744r2 Carried out by Ramis Safarov

I decided to answer such a banal question.

Assembly of the motor of this motorcycle, with examples of interchangeability of engine parts of the old-new model.

Almost before leaving for permanent residence in another collective farm, one old acquaintance, whom I had not seen for 15 years, turned to me and asked me to turn off the engine of his "Ant". To be honest, I did not have much desire to contact this Soviet rattler, to say the least ... But after thinking and playing in my head the situation that I would have to sit in a new place for a while without my favorite job, I agreed and immediately proceeded to repair it.

Especially, I will not delve into the essence of the disassembly within the framework of this article - I will outline only the main points and, based on my experience, I will try to describe the most common malfunctions and errors during repair.

The engine had the following symptoms before it was sent for repairs:

1. Bad start
2. Oil leak
3. Weak cravings
4. Increased noise during operation
5. The winder did not return to its place

1. Depressurization of the crank chamber, as well as wear of the oil seals
2. Poor build
3. Died piston
4. Bearing wear
5. Kickstarter return spring burst

Everything else, including the gearbox and the clutch, did not cause any complaints during operation. However, first things first.

Before a major overhaul, I don't wash the engines - I just drain the oil, pull it off the frame and get to work.

Remove the cylinder head (cylinder head).

The gasket under the cylinder head held well, as evidenced by the absence of oil leaks.

In the upper part of the cylinder, opposite the outlet window, we feel the development with our finger. If it gropes for a well-felt so-called "wave", "step" that is, a drop, then such a cylinder is no longer subject to further operation. It must either be bored to a repair size or buy a new one.

The development is well felt in the place where the piston rings do not reach the end of the cylinder. In the place where the piston rings do not work, the nominal factory size is preserved, and in the place where they work, the metal wears out. That is why a transition is formed at the border of these two sections, which is the greater, the greater the wear of the cylinder.

In my case, as expected - the development was well felt and the cylinder mirror was all in scuffs and scratches.

A bunch of hay, which blocked the flow of cooling air, as for me, did not add to the efficiency of the cooling system ... How is it possible to drive at all.

The piston was burst and, moreover, according to the good old collective farm tradition, it was pretty sandpaper treated.This is indicated by the numerous risks on its surface.

After removing the clutch cover and removing the kickstarter shaft, the reason for the winding lever hanging was found - a return spring that had burst in half.

The motor chain turned out to be stretched, but not critical.

Unbend the lock washer, insert a tin bar or stick under the tooth of the motor transmission sprocket, and unscrew the nut on the crankshaft trunnion (right-hand thread).

Unbend the lock washer, fix the inner clutch drum with a puller, which is a clutch disc with a welded piece of tire, and unscrew the nut (left thread).

We remove the basket from the shaft together with the chain and the sprocket.

We remove the cooling jacket, then, if the engine is not converted to magneto, remove the ignition interrupter cam. We hold the dinostarter rotor by the fan and unscrew the nut. If in this way it is not possible to hold the rotor, we fix the crankshaft with something and unscrew the nut.

We pull off the rotor with a puller. The rotor can be pulled off both with a regular puller and with a homemade one. Depending on the situation, I use both a regular and a homemade one.

We remove the flange on which the stator is planted and carefully inspect the plane of the connector for the interference of "cool handles".

How many I repair "Ants" so much and come across the fact that all kinds of "awesome handles" cover the oil channel with sealant through which the oil flows to the main bearing of the crankshaft and the oil seal. Already tired, honestly - how much can you? Why cover it up then.

It makes no difference to me, but how do you think the bearing and the oil seal should work without lubrication? Marvel at what happens to the main bearing when it runs dry.

Unscrew the bolts and half the crankcase.

Take-away crankshaft - to say that it is worn out means to say nothing ... The gearbox bearings, as well as the indigenous ones, went to the same place - to the crankshaft: to the trash heap. The checkpoint, with the exception of one fork, did not cause any complaints. By the way, the clutch too.

Now the question is: what to do with all this junk? Buy a "plasticine" crankshaft, no one understands who made it and put it into the engine. I was initially against this idea. In general, we found a used engine for a ruble and removed the crankshaft from it. Of course I had to tinker with him. Since his thread was clogged, I turned it around and straightened it with a scraper.

After thread dressing, I checked the crankshaft for runout. In vain I was worried - the beatings of the pins did not exceed one hundredth of a millimeter with a tolerance of three hundred parts. By and large, it would have been necessary to replace the bushing of the upper connecting rod head, but time was running out and the bushing was not very worn out. In all other respects, the crankshaft did not disappoint and this purchase can be safely called successful.

Everything else: CPG, cylinder head, gaskets, oil seals, bearings, motor chain, etc. decided to buy in the store. Although, by and large, the cylinder could be squandered and this will be limited. But the owner did not want to wait, but in vain.

New, now I have a manual for disassembling the TMZ engine. 🙂 ———————————————- → Disassembly (Part 2).

At your request, I am posting a video tutorial on assembling the TMZ engine. 🙂 ——————————————- → Part.

service center # TIMER # KIROVETS.

At your request, I am posting a video tutorial on assembling the TMZ engine. 🙂 ——————————————- → Part.

Replacing the podipnik and the oil seal of the kolin-shaft.

service center # TIMER # KIROVETS. The bridegroom of the new K744p3 and the continuation of the sowing season.

New, now I have a manual for disassembling the TMZ engine. 🙂 ———————————————- → Disassembly (Part 1).

Complete assembly of the new model TMZ motor. More information:

defective motor. calculated the losses. made a list of spare parts. we will order, we will receive the parcel, we will waste the CPG.

READ THE FULL COMMENT !! LINK . Assembling the T-200 engine in the early 60s (Ant motor scooter) How to get around.

A conversion kit has been developed for installing the TMZ engine on the New Holland TJ 530 tractor.

Assembling the TMZ engine. Part 2. Assembling the gearbox After pressing the Crankshaft, go to the box.

You can thank Dan for a good video and help the development of the channel at the card number sat: 427 six 2002 189 three 7592.

I decided to answer such a banal question.

Assembling the TMZ engine. Part 1. Pressing in the crankshaft We make the very first step in the project, where the main thing.

Scooter engine Ant Finish detailed assembly, some tips and tricks. Routine.

PART ONE: Dismantling the Tula motorcycle engine, to replace the output shaft and in search of the causes of poor performance.

Assembled a motorcycle. Replaced the rubber band on the petal valve, replaced the cuffs on the carburetor needle and the gasket.

FROM PERSONAL EXPERIENCE: An overview of the interchangeability of parts of Tula motorcycle engines, different years of production.

TMZ. Motor scooter ant. Check point Muravei. An illustrative example of gear shifting on the TMZ backwater motor (Muravei /.

At your request, I am posting a video tutorial on assembling the TMZ gearbox. 🙂 ———————————–.

Replacing the left oil seal of the shaft knees on the Tula engine, without splitting, by the barbaric method.

This is how I replaced the crankshaft seals. I did not remove the engine from the frame. If you did that too.

Gearbox repair Motor scooter Ant. In outline. We are here: Friends! I need your help. At all.

Repair of the engine TMZ 8481 D 280, MMZ 240, 245, YaMZ in Minsk. Buy Tutaevsky engine, internal combustion engine MAZ, MTZ, agricultural technician.

Replacing the podipnik and the oil seal of the kolin-shaft.

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Replacement of the TMZ 390 hp engine on YaMZ-7511 400 hp on the K-744 P3 tractor On the K-744 P3 tractor, the manufacturer was.

Installation of TMZ and YaMZ engines on imported equipment. We have already designed and manufactured conversion kits.

In this video I will tell you how to assemble a voltage regulator assembly with a starter relay with your own hands.

Fuel pump does not work

Bleed the system manually

There is no fuel pressure

wa in the fine filter cavity

start the engine on cold

cleaning, no fuel escapes

stop and loosen the bolt of the cross-

singing of the supply tube to-

fuel filter for fine cleaning

The section of the air path is closed by the emergency stop mechanism flap

Press the button on the damper drive

There is no characteristic “click”

Return the damper to a position that does not create resistance to the air flow by turning the damper drive lever counterclockwise until it stops

The high pressure fuel pump rack is stuck in the zero feed position

Remove the rail cap at the end of the high-pressure fuel pump (injection pump) housing and check the rail mobility with the effort of your fingers, moving it in the axial direction

The rod does not move in the axial direction or moves with great force or binding

Replace the high pressure fuel pump (TNVD)

The engine does not develop power

Clogged air filters

Check the readings of the air filter clogging sensor

Clogging sensor indicates a dirty air filter

Service air filter or replace filter

Deviations from technical requirements

The engine does not develop power

Dirty fuel filter elements

Bleed the fuel system with a manual fuel priming pump, successively loosening the bolt securing the inlet ("inlet") and outlet ("outlet") pipes of the fine fuel filter

The rate of fuel leakage from under the loosened “outlet” bolt is noticeably lower than the rate of fuel leakage from under the loosened “supply” bolt

Replace filter elements

The injection pump regulator control lever does not reach the maximum speed bolt

Move the drive lever to the position of the maximum idle speed and check with a feeler gauge the gap between the maximum speed bolt and the stop on the governor control lever

The gap is greater than 0.2 mm

Adjust the drive levers

The stop lever does not reach the extreme working position

Check engine power with disconnected stop lever drive

Adjust the stop lever actuator so that the stop lever is rotated clockwise

Air in the fuel system

Loosen the bolt of the fuel filter drain pipe (without the inscription and arrows on the filter housing) and bleed the fuel system with a manual fuel priming pump

Fuel escapes with air bubbles when the fuel pump handle is moved down

Tighten all connections of the fuel lines on the line from the fuel tank to the fuel supply pump, eliminate the leak

JSC "Tutaevsky Motor Plant" is a specialized enterprise that produces diesel engines for various purposes. The produced models have power from 350 to 560 hp. In addition, the company produces gearboxes and spare parts. The most modern modifications of engines with turbocharging and intercooling are coming off the assembly line of the plant. Such motors are economical and reliable in operation.

Tutaev motors have many advantages due to their design features. Main advantages:

• the inner part of the pistons is oil-cooled;
• the individual cylinder head is equipped with 4 valves;
• overpiston clearance is adjusted during motor assembly;
• high energy injection of the fuel system;
• the presence of a water-oil radiator.

Also, the advantages of TMZ engines include the use of world experience in the development of diesel engines. The development of many models is carried out with the participation of such market leaders as "Gould", "Male", "Getze". The production equipment is constantly updated at the plant.

They use universal engines for both heavy mining machines and special equipment, agricultural equipment and tractors. Traditional consumers:

• Minsk plant;
• Kirovsky;
• Bryansk Automobile Plant;
• BelAZ.

Today the company is looking for new sales markets. All manufactured products are tested for environmental friendliness and safety. All engines for cars are certified according to environmental class 3, and models for tractors - in accordance with the requirements of UNECE No. 96. Work at the plant is carried out in four main areas:

• motor;
• forging and pressing;
• release of gearboxes;
• foundry.

The main activity of the company is the production of motors. Diesel units of TMZ are the pride of the enterprise.

Official dealers distribute the plant's products throughout Russia. One of the largest representatives is the Beltkhsnab company. There are many spare parts for TMZ engines in the catalog.

Trying to find new sales markets, company executives are trying to put their engines on river vessels to replace old engines. This niche is considered one of the most promising. Today the plant is establishing cooperation with the ports of Moscow and Nizhny Novgorod, as well as the Donskoy and Lena basins. TMZ motors are also suitable for diesel locomotives. Railway workers are modernizing their cars by using new diesel engines. Tutaev engines are also installed on stationary power plants.

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.

Diesel Enginescollected on Tutaevsky Motor Plant (TMZ), technically are among the most modern in Russia, differing in efficiency, economy and reliability. Advantages of Tutaev motors are determined by their design features: this is a 4-valve individual cylinder head, the ability to adjust the optimal over-piston clearance during engine assembly, pistons with oil cooling of the internal cavity, fuel equipment with high injection energy, built-in water-oil cooler, fan drive through a hydrodynamic or friction clutch with automatic control ...

For more than 30 years, TMZ engines have been used as part of mainline road trains, heavy-duty dump trucks, large and extra-large city buses, agricultural and industrial tractors, off-road specialized equipment, diesel generator sets, road construction equipment. The multiple winners of the Paris-Dakar international rally, Kamaz-Master trucks, are also equipped with Tutaev engines.

On the basis of TMZ engines, our company produces diesel power plants of the AD series power from 200 to 315 kW, PD series diesel drives and diesel pumping units with HP (D) pumps, GRAT, GrAK, CNS, CN.

The table shows the maintenance intervals. engines TMZ, as well as, accordingly, the timing of the oil change and the frequency of changing the filter elements of oil and fuel.

1. Inspect the engine for leaks of fuel, oil and coolant, the normal condition of the external engine components

2. Check the oil and coolant level in the engine

3. After stopping the engine, check by ear the operation of the turbocharger and the centrifugal oil filter

4. At the end of the work, fill the fuel tank with fuel without waiting for it to cool down to avoid condensation of water vapor

5. Check the tension of the drive belts, adjust if necessary

6. Drain sediment from coarse and fine fuel filters. In winter, drain the sludge from the filters every day after the end of work.

7. Change the oil in the diesel engine crankcase

8. Flush the centrifugal oil filter

9. Change the filter elements of the oil filter

10. Check and, if necessary, adjust the setting of the fuel injection advance angle

eleven.Replace the filter elements of the fine fuel filter

12. Carry out maintenance of the engine injectors

13. Check the ease of rotation of the turbocharger rotor, if necessary, carry out its maintenance

14. Check and adjust the thermal clearances in the valve mechanism

15. Check the high pressure fuel pump, adjust if necessary.

16. Change oil and fuel for the upcoming season

17. Check the components of the electric torch device

18. Flush fuel sediment filters

Note .
ETO - shift maintenance
TO-1 - first maintenance, 125 hours of engine operating time
2TO-1 - additionally through one TO-1
TO-2 - second maintenance, 500 hours of engine operating time
TO-3 - third maintenance, 1000 engine hours
2TO-3 - additionally through one TO-3
Service station - seasonal maintenance

Powerful and economical TMZ engines are reliable and easy to use. However, it must be remembered that the lifespan depends to a large extent on regular and careful maintenance. Before using CAREFULLY study "Instruction for the operation of the power unit"supplied with each engine and follow all of its requirements. Pay particular attention to the following guidelines:

1. Follow the rules outlined in the "Running in a New Engine" section. During this period, the rubbing surfaces are running in.

2. The use of fuels, lubricants and coolants not specified in this section and the Instruction manual for the power unit, forbidden.

3. Is prohibited starting the engine from an external source of electricity with characteristics (voltage and current) or total capacity of storage batteries exceeding those specified in the operating instructions.

4. After starting, before switching on the load, the engine must be warmed up at the beginning at idle speed to a coolant temperature of 40-50 ºС, and then gradually increase the load as the speed increases to the rated one. The time during which the load can be increased to full should be at least 3 minutes. load up to the operating temperature specified in the operating instructions. Cold engine full load not allowed.

5. Not recommended engine operation at minimum idle speed for more than 10-15 minutes, except for warming up a cold engine after starting.

6. To avoid breakage is strictly prohibited turn on the starter when the engine is running or not stopped.

7. Engine operation with glowing indicator lamps for clogged oil or air filters not allowed.

8. To avoid damage to the turbocharger, before stopping the engine must run for 3-5 minutes at medium idle speed.

9. In the presence of slipping of the clutch when the pedal is fully released, as well as in the presence of "guidance" operation not allowed.

10. Maintenance must be done according to the section “Maintenance”.

In the article: Dismantling the engine of the "Ant" scooter, the process of complete disassembly of the TMZ engine was shown in detail, after which all parts were carefully examined and checked for acceptable wear and damage.

All the oil seals and bearings of the engine, the cylinder - it had to be bored to the repair size, the motor chain, and the gear of the first gear - did not pass the test for suitability for further operation due to wear of the bushing and something else. Not so much considering the age and "quality" of service of our "ant" ...

We managed to buy all the worn-out parts without any problems, so the only thing left was to collect “to the heap”, all this “Soviet junk”. What exactly we are going to do today.

Before assembly, all planes and engine parts are thoroughly washed and cleaned of dirt, oil and remnants of old gaskets, sealant. We pay special attention to the condition of the crankcase and threaded connections, the main work on repairing the crankcase, detailed in the article: Repairing the scooter engine crankcase, preparing ourselves a clean workplace, and proceeding to a very interesting and exciting activity ...

We put the right half of the engine on the blocks, clean and blow through the oil channel (marked with an arrow), degrease the plane of the dynastarter mounting flange, put a new gasket and be sure to cut it a little along the contour of the oil channel in the place marked with the arrow.

It is undesirable to apply sealant to this connector, as there is a danger that the sealant will get into the oil channel and cut off the oil supply to the oil seal and the crankshaft main bearing. What this leads to is written in the article: Repair of the dynastarter of the "Ant" motor scooter

We install a new oil seal in the dynastarter stator mounting flange, degrease the plane, apply a "blue" thread lock on the mounting bolts and finally tighten the bolts. Tighten the bolts very well, as they are constantly loosened, which leads to serious engine damage.

We turn the half over, heat the main bearing seat with a construction hairdryer and, using a mandrel, install a new main bearing (in our case) into the crankcase.

We take the other half of the crankcase, without fail we clean-blow the oil channel (marked with an arrow), insert a retaining ring into the main bearing seat and, in the same way, install the second main bearing in its place.

We are looking for a sheet of metal - of a suitable thickness (7-8 mm), we push our sheet between the cheeks of the crankshaft and in this position, using a mandrel, we press the inner race of the main bearing onto the trunnion.

The crankshaft of this engine was carefully checked for faults and the correct geometry, the main work on diagnosing the crankshaft is detailed in the article: Method for determining faults in the crankshaft of a scooter, motorcycle

Also, on this crankshaft, the bushing of the upper connecting rod head had to be replaced, this work is described in more detail in the article: Replacing the connecting rod bushing of the motorcycle "Izh-planet", "Jupiter", "Ant"

We put the crankshaft into the left half of the crankcase, the final installation of the crankshaft into the crankcase is carried out using a simple device, the details of the correct installation of the crankshaft into the crankcase can be found in the article: Engine repair of the Voskhod-ZM motorcycle, not with a sledgehammer. As they often like to do in "collective farms" ...

After the final installation of the crankshaft in the crankcase, we assemble the gearbox in the correct order, how to assemble the gearbox is written in the article: Repair and assembly of the gearbox (box) of the Ant motor scooter,

We lay a half of the crankcase with the assembled gearbox on the planks so that the shafts hang freely in the air and do not interfere with the work, degrease the crankcase planes, install the guide bushings (marked with arrows) in their places so that they protrude slightly above the crankcase plane (5-6 mm) , apply sealant to both halves and put a new gasket.

We lubricate the lip of the oil seal and the main bearing of the crankshaft with engine oil and put on the second half of the crankcase from above.

We fill the tendril of the spring of the gearbox copy shaft retainer inside the crankcase.

With a wooden mallet, tap the halves until they come together and tighten the crankcase mounting bolts.

We lubricate the main bearing with engine oil, the edge of the second crankshaft oil seal, then use a mandrel to install the oil seal in its place.

We put the retaining ring in its place.

We also install the crankshaft support bearing there and fix it with a second retaining ring.

Now it remains to put the piston group on the engine, check and assemble the clutch parts and install the kickstarter mechanism. Then you can install the engine on the frame.