Adjusting valves on a Ural or Dnepr motorcycle

Adjusting the valves of the Ural and Dnepr motorcycles.

In the gas distribution mechanism, the thermal clearance in the valve drive is regulated. In order for the valve to fit tightly on the seat, it is necessary that there is a gap between the valve and the drive parts when the camshaft cam is not acting on the pusher. If there is no such gap, the valve will rest against the actuator, will not sit on the seat and will not provide a tight seal. If, on the contrary, the gap between the valve and the drive parts is too large, this will lead to the opening of the valves being delayed. In both cases, this is a sign of unstable engine operation, intermittent operation (and if you add to this a poorly set ignition, incorrectly selected spark plugs, unadjusted carburetors, then the motorcycle will most likely refuse to start and run at all).

The clearance is adjusted on a cold engine. At the same time, it is useful to know that for lower-valve engines (motorcycles: M-72, K-750, Dnepr-12, MV-750) the clearance decreases when the engine warms up, and for overhead-valve engines (Ural and Dnepr motorcycles of modern models). Therefore, when adjusting, for lower-valve engines, a larger gap is assigned, and for overhead-valve engines, a smaller one.

An external sign of increasing clearances in the valve drive is a loud metallic knock in the cylinder heads on a warm engine. Signs of a lack of clearance are a drop in power from the Ural and Dnepr motorcycle engine and popping noises in the carburetor.

And so let's move on to the adjustments themselves:

1) Adjusting valves on motorcycles M-72, K-750, MV-750, Dnepr-12 The clearance must be adjusted as follows:

· Unscrew screw 9 Fig. 1 and remove cover 10 together with sealing gasket 8.

· Turn the crankshaft of the Ural or Dnepr motorcycle engine until the intake valve closes

· Loosen locknut 5 of the exhaust valve rod pusher adjusting bolt.

· By screwing or unscrewing the adjusting bolt 11 of the pusher 7, set the gap between the pusher 7 and the valve stem to 0.1 mm (the gap should be checked with a feeler gauge)

· Having established the gap, lock the lock nut 5, holding the adjusting bolt 11 with a wrench. Finally check the gap.

To adjust the intake valve clearance, continue cranking the crankshaft until the exhaust valve begins to rise and adjust the clearance as described above.

· Close the valve box with cover 10 with gasket 8 and securely fasten fastening screw 9 using a screwdriver.

When checking and adjusting the clearance, it is necessary to place a tray under the cylinder head, remove the cylinder head cover and drain the accumulated oil. Set the piston to i.d.t. compression stroke, turning the crankshaft so that the “B” mark on the flywheel aligns with the mark on the engine crankcase; You need to observe this through the inspection window in the engine crankcase with the rubber plug removed. In this position, both valves, intake and exhaust, will be completely closed, and their rocker arms should swing freely on their axles. Then you need to use a feeler gauge to check the gap between both rocker arms and the valves.

If the gap is incorrect, it is necessary to loosen the lock nut 1 (Fig. 2) and, by rotating the adjusting bolt 2 in one direction or the other, set the required gap. After this, tighten the locknut. The clearance is adjusted when the engine is cold; in this case, the gap should be equal to 0.1 mm ± 0.01 mm at the outlet, and 0.07 mm ± 0.01 mm at the inlet. If there is no or very small clearance, the valve will not fit tightly to its seat when closing; if the gap is large, the start of valve opening will be delayed.

The gap size should be checked if necessary. When adjusting the clearance in another cylinder, it is necessary to rotate the crankshaft one revolution (360 º), and then check and adjust the valves as indicated above.

3) Adjusting valves on modern Ural motorcycles (M-67, IMZ-8.103, etc.)

Next, two methods of adjusting the valves of a Ural motorcycle will be described.

The first thing I would like to note is that the gap between the valve stem and the adjusting screw on a cold Ural motorcycle engine should be 0.05 mm. The adjusting screws must not have clogged edges and must be locked.

· To adjust the clearances, remove the cylinder head cover and drain the accumulated oil. Then use the trigger lever to turn the crankshaft. As the intake valve begins to close, the exhaust valve clearance is adjusted, and as the exhaust valve begins to open, the intake valve clearance is adjusted.

Required Tools

Before you start adjusting the valves, you should prepare the necessary tools.
First of all, you will need a set of keys. In practice, you will only need one, but it is better to have everything on hand. The motorcycle valves are directly adjusted using feeler gauges. Depending on the motor model, different probes may be needed. On the M 72 Ural, a thickness of 0.1 mm will be required; for newer engines, for example, IMZ, it is better to use 0.05 mm. In fact, these are very conditional indicators. There is a small tolerance during adjustment, but under operating conditions of the power unit this does not affect its performance.

You will need to stock up on a small container to catch the oil; it can sometimes spill. Also, a rag will not be superfluous; it can be used to clean the engine from dirt. Let's see how to properly perform this repair.

How to adjust without a valve gauge on a Ural motorcycle

Adjusting the valves of the Ural and Dnepr motorcycles.

And so let's move on to the adjustments themselves:

1) Adjusting valves on motorcycles M-72, K-750, MV-750, Dnepr-12 The clearance must be adjusted as follows:

· Unscrew screw 9 Fig. 1 and remove cover 10 together with sealing gasket 8.

· Turn the crankshaft of the Ural or Dnepr motorcycle engine until the intake valve closes

· Loosen locknut 5 of the exhaust valve rod pusher adjusting bolt.

· By screwing or unscrewing the adjusting bolt 11 of the pusher 7, set the gap between the pusher 7 and the valve stem to 0.1 mm (the gap should be checked with a feeler gauge)

· Having established the gap, lock the lock nut 5, holding the adjusting bolt 11 with a wrench. Finally check the gap.

To adjust the intake valve clearance, continue cranking the crankshaft until the exhaust valve begins to rise and adjust the clearance as described above.

· Close the valve box with cover 10 with gasket 8 and securely fasten fastening screw 9 using a screwdriver.

3) Adjusting valves on modern Ural motorcycles (M-67, IMZ-8.103, etc.)

Next, two methods of adjusting the valves of a Ural motorcycle will be described.

Valve guides from vases on the Dnieper (Ural)

When I came to the conclusion that the valve guides were Khan, I came to the conclusion that the only alternative was the VAZ ones. Replacement did not cause problems 1- the head needs to be washed (after heating, you can wash off the horseradish) 2- Heat it up, I heated it in the oven of a gas stove (about 15 minutes), if there is an opportunity to find an electric one * (it’s easier with it) 3- Knock out the old bushings (you can buy a mandrel for knocking out, order a turner or make it yourself) a turner I know couldn’t turn it in time and couldn’t buy it (because it’s not available anywhere) so I did it myself )) with an angle grinder from the cylinder mounting stud (if you have a Urals, it won’t work) the main thing is don’t even think about knocking out the bushings when it’s cold!!!! Anyone who says otherwise is simply not technically literate!!! (saw the consequences) only heating!!! knock out the bushings, not with strong blows, with proper heating it is not difficult (heating is also not difficult) 4- VAZ bushings (short from the classics) will become like family ones, if possible, ask

turner to make new grooves for the retaining rings (27mm from the end that looks into the combustion chamber)

this is not necessary, but it greatly simplifies installation. The most important thing is that the bushings are sold as a set, long ones can be sharpened into short ones))) 5- Before installation, do not forget to soak the bushings for 2 hours in engine oil, heat the heads again (15-20 min) and press in new bushings, but not split the bushing (this happened to me) modify your homemade mandrel so that it does not damage the end of the bushing (if you are imaginative, there will be no problems) If you have retaining rings, then relax and hammer in all the way, if not - make a mark instead of them and carefully hammer in 6- After pressing, you definitely need to go through the bushings with an 8mm reamer and you will have to ream the seats, this is not difficult (I can explain in detail), but finding cutters (countersinks) is more difficult and they are expensive (although the process itself will take 30 minutes maximum), VAZ ones are suitable, 90,60,120 degrees, in the MT book it says 15,45,75, but this is the same (I’m shocked) 7- Grind in the valves, the easiest way is to apply paste to the valve, put a fuel hose on it (25cm is enough) and scroll the hose between your palms for a couple of minutes, periodically checking the seat (1-1.5mm should be ground in), if everything seems normal, wipe the paste from the valve and try again, then wipe the paste from the valve and seat and a couple more turn the valve once, if everything is normal, check the valve tightness by turning the combustion chamber to the light and look into the intake/exhaust channel, if you can see the light, repeat the procedure. Wash the head so that no abrasive remains

8- Assemble the head, but place two paranite rings under the springs (this will increase the preload of the springs and better sealing of the valves), feel free to place the seals on the valves and do not believe anyone who says that they will not hold up there and that the valves will not be lubricated. Ceramic metal is porous and oil seeps through the bushing in a volume sufficient for lubrication

My motorcycle (MT 10-36) works fine with these bushings and so far no wear on the oil seals has been noticed, but the oil darkens much later (it hasn’t darkened yet)

If you have any questions, I will be happy to help)))

Alexz

opposit.ru

Why adjustment is needed

With a small gap, especially if the pusher fits closely, low compression is observed. Even on a hot engine there is a gap. In this case, the engine operates unstably at any temperature; on a hot engine, characteristic knocking noises will be heard, and popping noises may occur in the carburetor;
If there is a large gap on the valves, they do not open completely. At the same time, the combustion chamber is poorly ventilated and is also not sufficiently filled with the fuel-air mixture. This leads to unstable operation of the motor.

If there are strong deviations in the clearances, the engine operates very unstable, to the point of being unable to start. Adjustments are made to avoid these problems.

Large valves in the heads of Ural 650

As you know, the shape of the KS heads of the Ural 650 came from five hundred, so it is somewhat inferior. Has anyone thought about or tried to enlarge the combustion chamber by boring, replace the seats by boring on a mandrel and push the valves in at least 42/38?

the valve was “shoved in”, it seems 40/37 foreign. intersected with RV "under 92"

I had to grind the plates and install reinforced springs. But the heads were new and the saddles were not worn out.

In principle, if you sharpen the seats a little and sharpen the valve, it is quite possible to install 42/38.

Dnepr 40/37 fits perfectly into IMZ 650 heads. Especially with already shuffling saddles, it allows old heads to return a second life.

IMHO, there is no particular need to increase the graduation rate much. 36-37 mm is quite enough for stock volume.

I suggest putting all your energy into the intake tract.

PS. TIT seems to have implanted huge valves, but how they didn’t intersect with each other remains a mystery to me. Only if with a narrow-phase RV, but then what is the point of increasing the flow area of the windows.

IMZ 650 38/35 KMZ 40/37 IMZ 750 41/38mm

nonsense. heads 750 rulez. At the same time, the fastening is like that of people

40/37 Dnieper ones were installed in the old heads, the saddles were loosened by hand. We didn’t notice much of a difference, the RV was standard. IMHO - it makes no sense to increase the valves on a 650cc engine. On the M-63, the intake tract was 25 mm, the carburetor diffuser was 24 mm (k-301), the compression ratio was 6.2, the power was 28 hp, on the M-66 the intake tract was increased to 28 mm, the compression ratio was increased to 7.0 power raised to 32 hp on the M67-36 the intake port was increased to 31 mm, the diffuser to 27 mm (k-301g) and the power was increased to 36 hp, on the IMZ-8.103 the intake port became almost oval 31/35 mm and the carburetor diffuser was first increased to 28 mm (k-63u carbs) and then reduced to 26 mm (k-65t) - this did not affect the power in any way. From my own experience I can say that with K-301 carburetors (24 mm) the engine works much more dynamically, without failures, than with K-301g (27 mm), the same with K-63, 65 carburetors - with a 26 mm diffuser, throttle response and thrust better than with a 28 mm diffuser. For the Urals, traction is much more important than maximum speed, IMHO.

Great excursion. Naturally, I’m not interested in the “pathetic” 650 cc, and not for the 750, not even the 825. There are 750 heads, they’re poppy, not round and they don’t have enough cooling fins, the question is, at least put in 42/38 valves, or better yet 44/38 or 46/40, for pistons at least 88, without grooving the spheres there is no way - the valves will hit each other, the compression ratio will be crazy and the pistons will be dangerously close to the valves. The German made a liter from a 750 IMZ - he relined the stock cylinders, it’s not clear that it’s almost a liter, what was going on with the cooling is also not clear. 2014 will not be the Year of the Liter. I feel it’s time to make my own with Volgov cartridges and such hefty self-sharpened shirts, I’ve already looked at the blank for 200, and the 750e heads won’t look good with them, like the Dneprov ones, with the latter they also bend the rods. Will there be enough meat if you grind the sphere 7 mm in depth and breadth? It’s a shame, but I’ve never held a 650 head in my hands. Mamzelev is silent about such a grooving procedure, but why not, you clamp it by the pin of the lid and use two feeds in coordinates and fine-tuning in volume? The studs will start to tighten, no problem, we’ll weld them and move them where needed, argon is within walking distance.

Do-it-yourself valve adjustment in the Urals

Detailed description of setting and adjusting valves on Ural and Dnepr motorcycles

Adjusting the valves on a Ural or Dnepr motorcycle is carried out infrequently, but this procedure is mandatory and allows you to keep the engine in full working condition. Despite the fact that the presented Soviet heavy motorcycles have different engines, their principle and adjustment scheme are the same.

What is thermal valve clearance?

Thermal valve clearance is the distance from the upper end of the valve stem to the pressure part of the rocker arm. This gap is necessary so that when the engine reaches high operating temperatures, with subsequent expansion of the metal, the optimal valve opening function is maintained. Of course, when cold, the engine may run unevenly or not at full power, fortunately, air-cooled engines quickly reach operating temperature and the valves begin to work as expected. Different units have different clearances, this is due to the materials from which they are made. For example, in the Dnepr K-750 motorcycle there is a gap of 0.1 mm, while more modern models of Soviet heavy motorcycles received a gap of only 0.05 mm. This means that the older K-750 was made of metal subject to a high degree of thermal expansion, while modern models are made of a more stable metal. To control gaps, special probes are used. They are made of steel plates of various thicknesses. Each probe indicates its thickness, and the degree of deviation with the indicated value is so small that under the operating conditions of these engines the error can be neglected.

Why is valve adjustment done on Ural motorcycles?

The valves have mobility in both directions, along their axis, which means the gap can increase or decrease. First, let's consider what happens if the gap decreases, right up to the contact with the pusher. First of all, power is reduced due to loss of compression. The engine heated up, the metal expanded, and the valve began to not close completely, making less contact with the seat, due to constant contact with the pusher. This can be determined by several signs - the engine has become harder to start, there is a noticeable loss of power when warming up, you can also hear the knocking of valves when hot and notice popping noises in the carburetor. Here you can find out details about setting up carburetors on a Ural motorcycle. On the other hand, if the gap becomes larger than required, then the valves will not open completely, the combustion chamber will become less filled with the fuel-air mixture and will be less cleared of exhaust gases. In both cases, the engine will perform noticeably worse, and in the most advanced cases, the engine will simply be impossible to start. By the way, the ignition in the Urals must also be adjusted.

Pistons and valve springs for boxers

With enviable frequency, questions arise on Opposite: which pistons to choose, is it possible to install Ural ones on the Dnieper or Dnieper ones on the Urals, how to distinguish pistons for 80 gasoline from pistons for 92, etc. and so on. Questions also arise about valve springs - is it possible to install non-standard ones, if so, which ones and how? What can be used instead of weak clutch springs?

This article will help you understand the diversity available.

So, PISTONS.

photo 1

Pistons are manufactured using different technologies (photo 1). Usually this is casting (for lower valves, as well as standard Ural and Dnieper valves). There is another technology called isothermal stamping (in common parlance they usually say “forging”, although this is not entirely correct). Both technologies have their pros and cons; In addition, sizes vary, so we will consider all options in order.

We look at Table 1 and Figure 1.

PISTONS FOR M-72 and K-750 are of interest primarily to antique lovers. They are not suitable for use in more modern motors due to the large distance from the pin axis to the bottom and the large mass. The pistons are interchangeable; they are distinguished by the presence of a groove for the second oil scraper ring on the pistons for the K-750 (photos 2 and 3).

STANDARD PISTON FOR 650 CC IMZ ENGINE (photos 4 and 5).

Cast piston with flat bottom, with two oil scraper rings. Provides a low compression ratio, requiring the use of gasoline with an octane number of 76-80. PROS: affordable price, widespread (in case of breakdown, you can find a spare piston or rings in any village), use of inexpensive fuel. Repair sizes available.

DISADVANTAGES: higher coefficient of thermal expansion compared to forged pistons, and, accordingly, a greater tendency to seize when overheated. Poorly resists burnout. Larger weight compared to forged pistons. Wide piston rings create increased friction against the liner, increasing mechanical losses. Losses can be partially reduced by removing the lower oil scraper ring, which will also reduce the weight of the piston. However, it is possible that oil consumption may increase.

STANDARD PISTON FOR 750 CC IMZ ENGINE (photos 6 and 7).

Forged piston with spherical bottom, short skirt and one oil scraper ring. Can be installed on both 750 and 650 cc engines. Provides an increased compression ratio, which requires the use of AI-92 gasoline. The pin is offset relative to the piston axis, which makes engine operation softer and reduces wear on the CPG. PROS: lighter than standard cast. Less prone to burnout. A lower coefficient of thermal expansion reduces the likelihood of a thermal wedge. Thin piston rings reduce mechanical losses in the ring-cylinder mirror pair.

CONS: high price. Low prevalence in spare parts. Use of Hastings rings in rare sizes. A reduced skirt THEORETICALLY could cause increased piston or cylinder wear. There are known cases of pistons burning out in the center when the mixture is very lean. There are no repair sizes.

PISTON MANUFACTURED BY “AUTOTECHNOLOGY”, STANDARD DIAMETER 78 MM (photos 8 and 9).

Forged piston with spherical bottom, standard long skirt, one oil scraper ring. The size of the rings is the same as on a forged Irbit piston. Installed on 650 and 750 cc engines. Provides an increased compression ratio for 92 gasoline. The pin is offset relative to the piston axis. PROS: with a full skirt, it has a mass as small as that of Irbit forged pistons. Exceptionally high quality of material (when struck with a finger it rings like crystal) and processing. Optimal skirt shape (barrel-shaped), providing improved lubrication conditions for the skirt. The price is at the level of Irbit forged pistons.

CONS: it is almost impossible to buy them anywhere other than Moscow. It is believed that the harder material of these pistons may cause accelerated cylinder wear. No repair sizes.

PISTON MANUFACTURED BY “AUTOTECHNOLOGY”, INCREASED DIAMETER 79 MM Piston produced by “Avtotekhnologiya”, increased diameter 79 mm (photos 10 and 11).

Structurally repeats the piston size 78 mm. It differs in the use of standard piston rings from the VAZ engine. PROS: Same as 78 pistons. Easily accessible rings make these pistons ideal for long trips. Some increase in working volume (up to 666 cubic meters). A good option for restoring a heavily worn motor.

DISADVANTAGES: the same as those inherent in pistons for size 78. A slight increase in weight can reduce the maximum engine speed.

I did not have a chance to examine the PISTONS FOR MOTORCYCLES FROM THE Kyiv PLANT personally, so the information is given from a third-party source: motodrive.com.ua The difference between them is in the bottom design and weight. All are equipped with standard opposed rings - 2 compression and 2 oil scraper rings per piston.

The disadvantages and advantages are the same as those of cast pistons for 650 cc IMZ engines.

PISTONS PRODUCED BY “AUTOTECHNOLOGY” FOR DNEPR MOTORCYCLES (photos 12 and 13).

They come with a diameter of 78 mm - for Hastings rings, and 79 mm - for VAZ rings. Forged pistons are structurally similar to the piston for the MT-10-32 engine with a trapezoidal displacer, but with one oil scraper ring. ADVANTAGES are the same as those of Avtotekhnologiya products for IMZ engines: low weight (noticeably less than the lightest cast ones), low coefficient of thermal expansion and tendency to jam, exceptionally high quality.

DISADVANTAGES are similar - low prevalence, concerns about accelerated wear of the cylinders.

I would also like to say something about the pistons with a diameter of 82 mm. The need for such parts is felt by owners of 720 cc Voyages, as well as tuning enthusiasts who want to bore their 650 cc engine to 720, or 750 cc to 825. Factory pistons for the 720 engine cannot be found on sale - “no, son, these are fantastic!".

The solution is to remake the car.

For example, a standard cast piston FROM a VAZ-2112 ENGINE (photos 14 and 15).

Remaking it is simple: make additional recesses in the bottom for the valves, bore the holes and press bushings into the opposite pin with a diameter of 21 mm. PROS: high prevalence of blank parts, ease of alteration. Using common inexpensive rings. Repair sizes available.

CONS: VERY large mass - almost 100 grams heavier than a forged piston with a diameter of 78 mm. Such a mass can negate all other work on boosting: the maximum engine speed will drop, the load on the crank and connecting rods will sharply increase. A cast piston will have a tendency to seize when overheated. Insufficient height of the sphere will reduce the compression ratio, which will have to be compensated by trimming the cylinder.

In short, this option is only suitable for resuscitating a 720 cc engine. It is absolutely not suitable for boosting; you need to look for lightweight, probably forged, pistons as blanks.

INSTALLATION RECOMMENDATIONS.

We install standard cast pistons in accordance with the books: we provide a gap between the cylinder and the piston of 0.08-0.10 mm for the Urals, 0.05-0.07 mm for the Dnieper. We place the piston pin into the piston with a tension of up to 0.0095 mm (for the Dnieper, a gap of up to 0.017 mm is possible).

Forged pistons, despite the fact that they have a lower coefficient of thermal expansion, are recommended to be installed with a gap of 0.08 mm, and for forced engines, which are characterized by high thermal loads, and 0.10 mm. The piston pin should have a sliding fit - that is, lubricated with engine oil, enter the piston when pressed by the thumb, but not fall out under its own weight.

VALVE SPRINGS.

Tuning enthusiasts or athletes often need to increase the stiffness of the valve springs in order to ensure that the valves do not collide with each other or with the piston at high speeds. As an alternative to opposed springs, valve springs from VAZ are usually offered - look at photos 17, 18 and table 2.

As we can see, in terms of dimensions, valve springs from front-wheel drive VAZs are closer to opposed ones, and complete with their upper and lower plates, they easily fit into the Ural heads (valve crackers differ slightly in the angle of the cone, however, VAZ plates work quite reliably with Ural crackers) . Classic springs are somewhat smaller in diameter and length, otherwise they are similar to figure-eight springs.

PROS: the increased stiffness of the VAZ springs reliably protects the valves and pistons from encountering torque, and also forces the valves to strictly follow the cam profiles at high speeds, which expands the operating range of the engine and allows increasing maximum power. Springs can be purchased at any auto store anywhere in the country.

CONS: the load on timing parts increases greatly, causing their premature wear. The ones that suffer first are the camshaft (rear journal) and especially the valve guides. The service life of these parts is reduced to 10-12 thousand km, so installing rigid valve springs is justified exclusively for athletes. Such springs are not suitable for civilian use.

OUTER VALVE SPRING FROM CLASSIC fits perfectly in size as a replacement for weak Ural clutch springs. They are much stiffer (see table 2), which allows you to increase the torque transmitted by the clutch. Usually 2 or 3, less often 4, Ural springs are replaced with classic ones, distributing them evenly. VAZ springs are almost four times stiffer, which ensures an increase in the clamping force of the clutch discs by 2, 2.5 or 3 times, respectively. However, the force on the clutch lever and the load on the cable also increase significantly.

PROS: Serious increase in torque that the clutch can transfer. This will be very useful for athletes and owners of highly accelerated engines, and simply for those who like to throw dirt on devices with a wheelchair drive. Availability of spare parts in any auto store.

CONS: catastrophic reduction in the life of clutch release parts. The cable lasts for a thousand to one and a half kilometers, and the slider and fungus lasts for a couple of hundred kilometers (a deep groove is rolled, after which the bearing crumbles; the only way to deal with it is to replace the ball thrust bearing with a bronze bushing). The large force on the lever greatly tires the hand when driving in the city. Often there is an effect of under-disengagement of the clutch, which makes it difficult to change gears and especially find neutral, making driving in the city very uncomfortable.

In short, another find for athletes, not suitable for everyday driving. With some stretch it can be recommended for use in rural areas with difficult road conditions.

Let me finish here. I hope the information collected will be useful to those who like to tinker with the Urals and Dnieper

VasyaPZ

opposit.ru

Valves for Ural motorcycle

Ural motorcycles are domestic vehicles. They are very popular because motorcyclists with any driving experience can afford them. The Ural motorcycle began to be produced back in Soviet times. Many people still use old models for driving today.

In general, Ural motorcycles are reliable. They rarely fail. In order for the engine to last for a long time, it is necessary to carry out preventive maintenance on time, which consists of checking and correcting problems in individual systems of motorcycle equipment.

How to grind valves with a drill?

pedestrian Thu, 19/07/2007 - 06:25

Viking, people, why are you using a screwdriver, your valves are crooked, and you are grinding them on the seat along the way.

Most of the heads that you have to work with are worn out, there is a large chamfer of the valve seat, there is play in the guides, valves with burnouts, or the working chamfer of the disc is worn out. 1 I interrupt the guide, there is a blog where you can buy factory blanks for your uncle turner. 2 I countersink (sharosh) the valve seats, 45, 15, 75 degrees, fortunately I have friends in a car service center, although I should buy myself a set of cutters so as not to beg

It is important that the working chamfer of the seat (45) is not wide, about 1 mm. 3 I'll give it away if the valves are used

for grinding the working chamfer, it happens that new lapans also have to be grinded because they are crooked. 4 After the above procedures, I rub it in with my hands, carefully for no more than 10 minutes with diamond paste, I don’t recommend rubbing for a long time at all, you will shorten the life of your head (moto head). All work takes 1 day, costs $5 and the head is like new. I also advise you to polish the channels, the outer and inner surfaces of the valve plate, which will add performance to your engine, and it’s much more pleasant to assemble such units.

Ps It is more convenient to polish the channels with a screwdriver.

opposit.ru

Adjusting the valve

The procedure for adjusting clearances on a Ural motorcycle requires care and attention, since it is necessary to accurately set a specific value.

The process itself can be divided into several sequential actions:

First you need to remove the cylinder head cover. Sometimes there may be some oil present that needs to be drained. At this stage, you should turn the crankshaft until one of the pistons is at the top (dead) point. This can be determined by special marks located on the flywheel and engine crankcase. When the piston is in the desired position, these marks should coincide. This process can be monitored through a special hole, often closed with a special plug. Measure the gap with a special feeler gauge measuring 0.05 mm. In case of discrepancy, you should proceed with the adjustment, which is made by a bolt located on the rocker arm

It is very important to loosen the locknut before unscrewing it. Once the desired gap size is set, tighten the locknut back. We check this parameter again and then install the previously unscrewed cover in place.

Adjusting the valves of our boxers (Page 1 of 12)

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1↑ Topic by mexanik62 03-01-2013 11:09:31

mexanik62
Mechanic from the 30s.
Inactive
Name: Uncle Vitya

From: Evpatoria
Registered: 03-08-2011
Messages: 10 831
Reputation: 1 136
Motorcycle: 12-volt K-750, ZAZ Sens Hatchback

Topic: Adjusting the valves of our boxers

The valves are adjusted in COLD mode (10 - 20 degrees above zero). There are two methods: First: It is used when there is no procedure for adjusting the gaps, it is difficult to set TDC or after repair. Rotate the crankshaft until the intake valve is completely closed (the rocker arm is hanging, the pusher is pushed in as far as possible. Set the exhaust valve clearance. Without removing the feeler gauge, rotate the crankshaft until the feeler gauge clamps or the rocker arm stops swinging and set the intake clearance. Repeat for the second boiler. For greater accuracy, adjust again. Second: Set the pistons to the TDC position. Set the gaps on the boiler where both rocker arms swing. Rotate the crankshaft 360 degrees and adjust the gaps of the second boiler. Check the gaps. Method of setting the gap without a feeler gauge. On our motorcycles, the thread pitch of the adjusting bolt is 1.0 mm. Let's take advantage of the fact that the rocker arms are equal-armed (there are none at all on lower valves). Use the adjusting bolt to set the position in which the rocker arm does not swing and the pusher rod easily rotates with your fingers (there is no play). Loosen the adjusting bolt 1/12 of a turn (that is, there are 6 edges on the head of the bolt and 6 corners and you need to turn it so that the edge replaces the corner, this will be 1/12 of a turn in size 1/12 = 0.08 mm approximately and in general it is similar to the existing gaps). Clearances in our motorcycles: M72 and inlet and exhaust 0.1 mm K750 inlet 0.07 mm exhaust 0.1 mm Overhead valve Dnepr 650 cc and inlet and exhaust 0.07 mm Overhead valve Urals 650 cc and inlet and exhaust 0.05 mm Overhead valve Urals 750 cc inlet 0.05 mm exhaust 0.07 mm The main thing to remember is that there should be a gap and it is better to let it be more than less. A reduced gap (well, the engine whispered) is a direct road to valve burnout and impacts on the piston. Sometimes there are cases when a slightly warmed-up engine does not pull and starts to fail - it is necessary to increase the gap!

Edited by mexanik62 (04-08-2016 12:12:30)

2↑ Reply from Ural*4uK 03-01-2013 13:39:16

Ural*4uK
Elder
Inactive
Name: Igor

From: Russia, Bryansk region, Mglin
Registered: 03-03-2012
Messages: 1 451
Reputation: 39
Motorcycle: Ural IMZ 8103 with sidecar

Re: Adjusting the valves of our boxers

hmmmmm. Why complicate everything so much, put it at TDC and use a feeler gauge to make the gap and it’s fine!! I don’t know about others, but from time to time the control nut would loosen and the setting would go wrong. I had to adjust everything all over again, although I tightened the nuts with decent force.

3↑ Reply from solex 03-01-2013 17:36:41

solex
Experienced
Inactive
Name: Artem

From: Ukraine. Lugansk region.
Registered: 24-01-2012
Messages: 107
Reputation: 5
Motorcycle: Ural IMZ 8.103-40

Valves for Ural motorcycle

March 24

LiveJournal

What can result from untimely valve adjustment on Ural motorcycles?

Owners of Ural motorcycles very often encounter problems with valves. They need to be configured in a timely manner. Not every modern motorcyclist knows how to adjust the valves on a Ural motorcycle. To do this you need to have certain knowledge and skills.

You can make adjustments yourself. Initially, you need to familiarize yourself with how to do this. Instructions for working with Ural valves are not complicated. Every motorcyclist can figure them out.

Important: It should be remembered that in order for the Ural engine to last for many years, it is necessary to adjust the valves every two thousand kilometers. This frequency was not chosen by chance.

It has been experimentally proven that it is after overcoming two thousand kilometers that the valves of Ural motorcycles begin to fail. The gap between the valve base and the pusher or rocker arm (depending on the engine type) becomes larger

This frequency was not chosen by chance. It has been experimentally proven that it is after overcoming two thousand kilometers that the valves of Ural motorcycles begin to fail. The gap between the valve base and the pusher or rocker arm (depending on the engine type) becomes larger.

As a result, every owner of Ural motorcycle equipment needs to adjust the valves. This will allow you to enjoy using your vehicle for various purposes for many years. With adjusted valves, the engine will always operate properly.

Valve guides motorcycle Ural

Adjusting valves on a Ural motorcycle

In order to adjust the valves on Ural motorcycle equipment, it is necessary to divide the process into several stages.

How to adjust valves on a Ural motorcycle

They are:

unscrewing the screw and removing the cover along with the gasket,
turning the crankshaft until the intake valve closes,
loosening the counterbolt, which is located on the exhaust valve stem pusher,
regulating the gap between the valve base and the pusher or rocker arm. The gap should be 0.1 millimeters.
setting the gap. It consists of screwing the locknut into a certain place.

To adjust the intake valve, you must first turn the crankshaft until the exhaust valve is completely closed. Only then can the gap between the base of the intake valve and the pushrod or rocker arm be adjusted.

The sequence of actions for adjusting the intake valve on a Ural motorcycle is practically the same as that used to adjust the exhaust valve.

Important: When adjusting one valve, you must not forget to adjust the other. Otherwise it will lead to engine malfunction

Many motorcyclists do not consider setting the valves on a Ural motorcycle too complicated. It can be done at home without any extra costs, which will lead to savings on the services of various motorcycle services.

Motorcycle URAL M67-36 — DRIVE2

They gave me a Ural motorcycle for my birthday. An ordinary Ural M67-36, my same age as I am, produced in 1980, with a mileage of 19,000. The motorcycle was found in the Ryazan region, in a village barn, littered with rubbish, where it stood idle for 20 years. They poured gasoline, put on the battery, and to the surprise of everyone the motorcycle started, but the way it worked, the sounds it made... It was decided to rebuild the motorcycle, without painting. I am completely satisfied with its original paint job; it is in good condition for this type of equipment. It took a year and a half to find spare parts and work.

At this stage, field tests are being carried out, carburetors are being adjusted, the electrics are constantly giving surprises, charging has disappeared, the Saruman ignition is a separate issue, the wires are different from the circuit, find it yourself)

Here is a list of spare parts. A new USSR crankshaft was purchased on Avito. Avtotekhnologiya piston (79mm) for AI92 gasoline Carburetors Pekar K 68. China, on one the needle immediately broke off, on the other the thread was not cut. I did not drill the carburetors. New sample heads. Valves:— Freccia inlet valve— Exhaust valve AE Germany— Ural plate under the VAZ cracker— Freccia guide New flywheel + modified disk from 412 Muscovite. Saruman ignition with optics + camshaft, pushers, bearings, seals, rubber bands , cables, etc.

The box is a new model, with reverse gear, the rear one flies out. We've gone overboard and it's crashing)

www.drive2.ru

What is thermal gap

The term thermal clearance refers to the distance between the rocker arm and the upper end of the valve. This allows for the inevitable thermal expansion of engine parts to ensure optimal operation of the valve mechanism. The disadvantage of having such a gap is the low stability of the engine when starting when cold, but it works great when fully warmed up.

It should be remembered that the gap must be appropriate for the engine model. On older models, the alloys are less stable, so it is recommended to set this indicator to 0.1 mm. On more modern engines, the gap can be set within 0.05 mm.

Adjusting motorcycle valve clearances

Adjusting valve clearances is necessary to extend the life of heads and valves. These clearances are thermal and are intended to compensate for the expansion of the valves while the motorcycle engine is running.

An increase in the gap leads to a sharp drop in power , as a result of loose closure, but if the gaps are too small, the valve cover will run out, which will lead over time to the destruction of the root rod.

In order to understand whether there is a problem with clearances, it is necessary to start the engine. When its parts are not yet warmed up, you can hear a distinct, characteristic chirping sound as a result of the beating of the valve cover. The absence of such a sound when the engine is warm after a trip can also confirm your guesses.

The valve clearances of a Ural motorcycle or any other must be checked according to the regulations specified in the passport for the technical device or instructions. According to information from the manufacturer, every 3000 km or when operating the vehicle for a period of 3 months or more, it is necessary to check the clearances or adjust the valves.

Sequencing

To do this, use a tool with a thickness of no more than 0.07 mm. The entire procedure should be carried out only on a cold engine, since even slight heating can throw off all indicators. In order to understand the clearance on the valves of a Ural motorcycle, focus on the feeling and the average value of 0.05-0.07 mm. Your dipstick shouldn't fall through, but it shouldn't require much force to push between the valve and rocker arm. Otherwise, adjustment is needed.

To adjust, you will need to tighten or loosen the bolt located on the rocker arm. Before doing this, loosen the control nut. ATTENTION! These bolts are quite fragile and can easily break if over-forced, so use a comfortable tool and do not overdo it.

Once the adjustment is complete, reinsert the dipstick. If it fits tightly, secure the bolt with a locknut.

To check the correctness of the actions performed, after reassembly, start the engine and evaluate the changes in its operation. Excessive clattering and clicking should go away, and the engine should produce more dynamics and speed when driving.

As you can see, valve adjustment is a fairly simple process that all owners of domestic motorcycles have to become familiar with. Those who actively use a motorcycle can make adjustments once every month or two. If you are focused on mileage, in the absence of problems or extraneous sounds, you still need to check the gaps.

Other domestic boxers and their settings

When setting the gaps, you must remember that it is better and safer to increase the gap than to decrease it, since this will only lead to a loss of power and the appearance of an unpleasant, but not critical sound. Otherwise, the valves will simply bend or break, which will result in expensive repairs. If you don’t know the correct values or don’t have a tool, it’s better to entrust this procedure to experienced comrades or specialists.

Clearances on domestic heavy motorcycles:

Ural 650 – intake and exhaust valves of 0.05 mm each;
750 – inlet 0.05 mm, exhaust – 0.07 mm;
Motorcycle Dnepr - intake and exhaust valves of 0.07 mm;
K-750 – inlet 0.07 mm, exhaust – 0.1 mm;
M-72 - 0.1 mm intake and exhaust valves.

After adjustment, carefully inspect the engine, listen to how it works, do not miss anything, there is no need for haste. A mistake made will lead to rapid burnout of the valves or strong impacts on the pistons.