Adjusting valves on an Alpha 110cc moped

How to set timing marks on an alpha moped

Checking the timing belt by marks on the Delta EX 50 moped engine 1P39FMB (139FMB)
Comments from those interested:

Roman Khimchenko 2 weeks. reverse And if it doesn’t match WHAT to do

Vladimir Voronov 2 weeks. reverse Set it to match.

Vladimir Voronov 1 month ago This is nice. )) And of course there will be new videos, just wait a little.

Vladimir Voronov 1 month ago Yes! Another thing, don’t install two gaskets; it won’t make things any better; an increase in the combustion chamber will result in a drop in power.

Hunter38767 3 weeks reverse And if you have a 50cc head and a 72cc piston, then you need to change the head.

Hunter38767 3 weeks reverse Two gaskets are not allowed, look, the valves may be overtightened, unscrew the two caps on the head, and look at the gap, it should be 0.05 on the feeler gauge. But if they hit the piston, then there is no gap.

Sergey Vasiliev 1 month back Vadim, thank you, I read a lot of useful information, thank you, I will be glad to see new videos on alpha, I’m really looking forward to it

Arkady Novoselov 1 month back, well done, thank you for you!

How to Tension the Timing Chain on an Alpha Moped

Photo report: how to check the drive chain of a scooter?

In life it is always like this: one wonderful thing, another bad. The same principle applies to various types of manual transmissions. Chain transmission was no exception. On the one hand, there is nothing simpler, more reliable, simpler, more compact and cheaper than a chain drive.

On the other hand, we get endless hemorrhages with chain stretching, sprocket wear, endless cleaning and lubrication, maintenance and stretching of the chain itself. But nothing can be done, the gearbox has many advantages over other types of mechanical gears, since these types of gears are used almost everywhere.

In general, now we will not talk about the chain drive as such, but about a method for diagnosing chain synchronization, which drives the scooter .

To change or not to change?

Let's say you're using most of your engine: you're replacing gaskets, crankshafts, gaskets and other things, but you're hesitant about replacing your timing chain with a new one. There is no doubt in your mind that you should replace it with a new one as soon as possible. And now I will explain why.

See for yourself: the average lifespan of a chain is approximately 18,000-20,000 km (personal experience), which is approximately the same as the average life of the engine itself. And for example, after driving 6000 km, the crankshaft jammed or the engine leaked, or something else that required complete disassembly of the engine. Naturally, you disassemble the engine, replace the crankshaft with a new one and leave the chain, which by that time has exhausted a third of your resource.

READ How to Twist Mileage on Accent

So what's going on? After 12,000 km the chain will fail and become unusable and the crankshaft and other parts will start to work and you will, if not want, have to halve the engine again through one chain. It's necessary? The chain is a consumable item. Never skimp on this!

check

Personally, I never check the time. I just throw them in the trash, no matter how wonderful they seem to me. For me it's a chain. This is a consumable item, the same as a spark plug, oil or oil seal. But if it's important to you or money is stressful, you can use your old grandfather.

Alpha tensioner repair

Tensioner repair £149.

We stretch the chain along its length, squeeze it with our fingers and try to position it in a horizontal position.

READ Replacement Timing Chain Volkswagen Jetta 1.4

To be clear, I took a new and very worn chain, connected them and checked for horizontal bending. As you can see: the new chain (above) has made a slight arc and is worn and no good, like snot, almost 90 degrees.

The worn chain was almost an inch longer than the new one.

How to replace the chain of scooters?

It's very simple, friends: remove the engine from the frame, disassemble it and replace the chain with a new one. There are no special secrets in this, and there are also no special ways to cheat fate without disassembling the engine. The chain can only be replaced by completely disassembling the engine.

The timing chain is not intended to be riveted or riveted in any way. It can be easily twisted or twisted while riveting and this is the correct way to ensure that the chain in the engine is pushed against the sprocket and luckily it can work and possibly bend the valve. And one more thing: a beginner will not be able to rivet a quality network. This work is not as simple as it might seem at first glance. So don’t suffer from debris, but disassemble the engine.

READ Replacing Timing Chain Honda Cbr 600 Rr

How to set the chain to pull?

But you won't receive or configure it, and it won't interfere with Google or Yandex searches with such queries. The chain in the scooter engine is tensioned automatically. And if it is stretched so far that it begins to fly or jump through its teeth, feel free to disassemble the engine and replace it with a new one. There are no miracles there.

Motorcycle chain

Without a chain, your motorcycle simply won't move.

The chain for a motorcycle is a very important element of its operation, although it is quite simple. Motorcycles don't run without a chain.

Chains are sold riveted at the manufacturing plant, or they can be open. These chains come with a link with a riveted lock. Riveted chains are considered more reliable. But manufacturers claim that the new locks are the most durable.

Each chain is marked. The marking numbers indicate the pitch and width of the chain links. This data is usually standard. The letters indicate the following: the strength of the rubber seal and its shape. These data may differ for each manufacturer. This is why it is so important to choose a chain that will suit the brand of your motorcycle. A suitable option can be selected in the catalogs.

As long as the factory lubrication is maintained and used on the chain, the chain will not cause any noticeable problems. Moreover, the constant improvement of seal forms makes it possible to reduce friction forces.

Problems with the chain arise when the rules for operating motorcycles are not followed. What can happen? The chain may break and the rear wheel will jam. Damage to the motorcyclist's leg is also possible. Chains can stretch over long periods of use. A chain that is not suitable for the motorcycle will fail faster.

Cases when the chain must be replaced:

• The rivets on the links are lost
• The rollers are damaged
• Connections are covered in rust
• The chain is worn to its maximum value
• Cracked rubber seals
• The chain does not stretch to the required size.

Table. Designation and application of motorcycle chains.

Motorcycle final drive chain care

Proper care of the chain will greatly increase the period of its safe use.

Every five hundred kilometers it is necessary to lubricate the chain. This should also be done if you are caught in the rain. Carry out this procedure before leaving. And there is no need to skimp on oil. To do this, pour the oil into a small container and use a brush. The motorcycle is placed on a stand; the rear wheel must be rotated while lubricating the chain.

Warning. It is not advisable to apply a lot of oil to an open chain, since by attracting dust while driving, the chain will begin to wear out and squeak faster.

For open circuits, it is better to use an oil spray in the form of a can. And closed chains can be generously lubricated with oil.

Before lubrication, wash the chain, especially if it is dirty. To do this, you can use either a liquid sold specifically for this purpose or kerosene. After the chain has completely dried, you can lubricate it.

Pay attention to the rear wheel. If it is shifted to the side, the tension will be uneven. It should be remembered that the life of the chain is greatly influenced by how you ride your motorcycle. By accelerating at top speed, you contribute to rapid wear of the chain. The chain should not be too tight or too loose. This will damage the chain elements and shorten its service life. This is why it is so important to regularly check chain tension. You can find out how to tension a chain on a motorcycle from specialists or on our website.

Motorcycle chain tension

To check the chain tension, rotate the wheel and observe the condition of the chain at maximum tension. Now place the motorcycle on a stand and check how much deflection the chain has. The normal position is when there are two to three centimeters between the two parts of the chain, upper and lower.

For qualified chain tensioning, you can contact a service center. But if you want, you can do it yourself.

The main thing is to strictly follow the established rules.

• To adjust the chain, there must be a certain load on it, so during the procedure, ask someone you know to sit on a motorcycle.
• Prepare your tools for work. You will need 17x19 and 13x14 keys.
• The motorcycle is on a stand. Using a 17x19 wrench you need to unscrew the shaft on which the rear wheel spins. The wheel will loosen and can be moved with the tension bolts.
• With the second wrench, 13x14, you need to unscrew the lock nuts, which are located on both sides of the wheel.
• The chain tension on the motorcycle begins directly. To prevent the wheel from moving to the side, the adjusting bolts must be pulled evenly. When tensioning the chain, periodically check with your hand how tight it is. Just press it with a little force to do this. The chain should not be very elastic. This can lead to rapid wear.
• If the tension is correct and sufficient, first tighten the locknuts of the tension bolts. And after that you need to tighten the rear wheel shaft.

All operations have been completed. You can once again ride your motorcycle on an exciting journey without fear that it will let you down.

How to replace the timing chain in an engine

Having decided on such an action as replacing the timing chain of a scooter, you need to decide on how to implement your plan.

There are two replacement options:

How to change, everyone decides for themselves. Both methods, advantages and disadvantages are described in detail below.

With disassembly

You should choose the right tools - generator and variator pullers (you can make them yourself), a kickstarter sprocket puller, 8, 10, 12 and 17 mm sockets, a hammer, two screwdrivers (flat, Phillips).

The engine is removed from its place, the oil is poured out, all parts are wiped and cleaned. Next, remove the muffler and cooling casing. We remove the generator only with a puller. To do this, unscrew the bolts from the impeller and remove it from the rotor. It is necessary to fix the rotor with a puller and unscrew the nut. Then we tear the rotor off the crankshaft journal. Remove the variator cover. Also, secure the impeller with a puller, unscrew the nut, and remove the variator from the axle.

Below the variator is the kickstarter gear. Likewise, a puller is required for it. Then we clean the cylinder connector, valve covers and cylinder head. After unscrewing the bolts on the valve covers, remove it. Next, remove the scooter's timing chain tensioner. After unscrewing the bolts on the cylinder head, we pull out the camshaft bed.

Next, remove the chain from the camshaft and pull it out of bed. To avoid losing the guide bushings that center the parts relative to each other, you need to remove them and put them away. We remove the cylinder head, the cylinder itself, and the piston (to do this, remove the retaining ring and pin from the upper connecting rod head).

After unscrewing the bolts on the crankcase cover, tapping it a little, remove it from the engine. We take out the starter intermediate gear, use a screwdriver and a hammer to unscrew the overrunning clutch nut (clockwise) and remove the gear and housing from the trunnion. We reached the chain!

Remove the protective shield from the oil pump. Place a metal stick under the chain, twist the nut on the oil pump sprocket, remove it and remove the chain.

No disassembly

We take the following tools: a Phillips screwdriver, pliers, a new chain and a special puller. More details about it will be below. We flare the new chain - to do this, use a puller to press the pin out of the joint of the links, but not completely.

A little about the puller

It is called a timing chain puller. It can be made by a turner by turning a threaded extruding pin and rolling a strong pin into it with a diameter similar to that of a chain pin. You can purchase a ready-made bicycle one. Just narrow the pin a little to the desired size.

Remove the cooling casing from the scooter engine, then the cylinder head cover. Next you need to remove the chain tensioner. We remove the camshaft bed, take out the shaft, remove the star.

We take the puller, center it with the pin, and gradually press out the pin. You can press it out completely, it will not be useful. We compare the links of the new and old chains, thread the wire into the seat of the pin and fix the ends of both chains. We turn the cooling impeller counterclockwise, gradually replacing the old chain with a new one.

Then we separate the ends of the chains, throw out the old one, and combine the new links from the ends. We check the alignment, install the pin, and use pliers to carefully press the pin in so as not to damage the new chain. We first check the mobility of the links. We finalize the pin with a puller. Again we control mobility. This point is very important: if you install the pin unevenly and miss it, it will begin to rest against one of the links and squeeze out the next one.

As a result, the subsequent pin or link bends, causing it to jam and become immobile.

Next, we assemble the engine in reverse order, placing marks on the rotor. When installing the camshaft bed, after tightening the nuts, you need to check the valve clearances with a feeler gauge. Upper valve – inlet: 0.05mm, lower – exhaust: – 0.1. The feeler gauge should fit freely between the valve and the adjusting bolt.

Then install the chain tensioner. We unscrew the bolt on the top of the tensioner, install a screwdriver in the groove, and, turning it, push the rod back. We fix everything else back according to the diagram.

Source

Setting the timing belt on a delta moped

1. Install a new cylinder head gasket.

ATTENTION!

The cylinder head gasket is made of soft metal (copper, aluminum) and after tightening the cylinder head nuts it is deformed, thereby ensuring a tight connection. Reinstallation of the cylinder head gasket is not permitted.

2. Install the timing chain guide.

3. Install the cylinder head.

4. Set the piston to TDC according to the marks on the flywheel. This is usually the "T" mark on the flywheel. Align the mark with the tide on the engine crankcase.

ATTENTION!

The following operation is one of the most important when assembling the engine. It is important to align all the marks very accurately. An error in installing the chain even by 1-2 teeth will result in the engine not working correctly, and it will probably even lead to serious damage to the timing and cylinder-piston gas parts when trying to start the engine!

5. After making sure that the timing chain has not jumped off the drive sprocket on the crankshaft, install the camshaft into the cylinder head, at the same time putting a chain on its sprocket so that the marks on the camshaft sprocket are parallel to the plane of the edge of the cylinder head, and the cams are directed downward (inside the head).

6. Install the rocker arm support, orienting it according to the installation marks. Lubricate the cams and camshaft bearings.

Video on this topic

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#41 How to determine the alpha chain stretch of a magnifying glass?

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Spare parts for scooters in Belarus Online store in Belarus https://scooterbaza.by/ Group in contact https://vk.com/scooterbaza.

Alpha 110 (Change timing chain)

They brought in a moped (Alpha 110) with a complaint about a foreign knocking noise in the engine, as it turned out that it was loose timing chain. Foam.

Replacing the camshaft tensioner and Delta timing belt

Alpha 110 (Replacement of magnet chain)

Foam filter for Alfa moped https://goo.gl/MF6F3b Digital thermometer.

Before you start adjusting the valves

Therefore, after purchasing a new Alpha RX, I checked the valve clearance. For this procedure I had to buy a set of probes. In our case, you will need a probe with a thickness of 0.05 mm.

In order to calmly begin adjusting the valves, I had to unscrew the safety bars. For this we need a key of 8.

To get to the valves, you need to unscrew the valve covers located on the top and bottom of the cylinder head. To do this we need a 17 wrench. I used a spanner.

Let's start adjusting the valves

Let's start with the intake valve, which is located at the top of the cylinder head. We'll need a key for 9. Yes! Not 8, not 10, but 9! Good thing I had a set of sockets in the car. But it is better to use a spanner wrench, which conveniently unscrews the pusher fixing nut on the rocker arm.

Then we need a feeler gauge with a thickness of 0.05 mm, which must be inserted between the pusher and the valve stem. By rotating the pusher, we reduce or increase the thermal gap until the probe moves with slight tension. After tightening the fixing nut, we again check the gap with a feeler gauge, which could have gone astray.

In a similar way, we begin adjusting the exhaust valve.

Setting TDC on Alpha

To start adjusting the valves on the Alpha moped, you need to set the top dead center. To do this, remove two covers on the rotor cover. Rotate the rotor until the T mark appears.

To accurately control this process, you need to remove the timing sprocket cover. To do this, on the opposite side you need to unscrew the clamping bolt, which can be unscrewed with a 10mm wrench. Remove the timing chain sprocket cover carefully so as not to damage the gasket.

The star has a mark in the form of a dot. It should be aligned with the mark on the head body.

To easily turn the engine mechanisms, I unscrewed the spark plug, reducing the compression to nothing.

Now you can begin adjusting the valves on the engine.

How to tension a chain on an Alpha moped - step-by-step instructions

To simplify access to the necessary components, first remove the rear left passenger footrest. The moped must be placed on the center stand. It is also advisable to unscrew the bolt and remove the exhaust pipe. If this is not done, the ratchet heads cannot be used.

Next, take two keys - 17 and 14 mm. You need to unscrew the nut to loosen the wheel axle. The nut is unscrewed, but not completely. With the second key you need to hold the axle on the reverse side so that there is a stop. If you don't hold it on the reverse side, the axis will spin.

Tools for replacing a chain on a moped

Open-end and box-end wrenches are used. In total, you will need four keys with a diameter of 10, 14, 17 and 24 millimeters. Depending on the moped model, instead of a diameter of 24, you may need 22 mm. If you have sockets and ratchets, you can replace some of the keys with them.

To tension the chain you will need wrenches 10, 14, 17 and 24

Just in case, it is better to stock up on a flat-head screwdriver; it will allow you to lift the bolts if they cannot be removed by hand.

To change or not to change?

Suppose you are overhauling your engine: changing oil seals, crankshaft, gaskets and other devices, but you doubt whether to replace the timing chain with a new one or not. If you have any doubts, change it for a new one at the first opportunity. And now I will explain why.

See for yourself: a chain has an average service life of approximately 18,000-20,000 km of a scooter (personal experience), approximately the same as the average service life of the engine itself. And for example, after driving 6,000 km, the crankshaft jammed or the engine leaked, or something else happened that requires complete disassembly of the engine. Naturally, you disassemble the engine, replace the crankshaft with a new one, and leave the chain, which by that time has exhausted a third of its service life.

And what happens? The chain, after 12,000 km, will exhaust its service life and become unusable, but the crankshaft and other parts will be in good order and whether you like it or not, you will have to halve the engine again, because of the chain alone. Is it necessary? The chain is a consumable. Never skimp on it!

Personally, I never check timing chains. I simply throw them in the trash, no matter how awesome they seem to me. A chain is a consumable item for me, just like a spark plug, oil or oil seal. But if you are important, or money is tight, you can use the old fashioned way.

How to adjust and tension the chain?

There’s no way you can tighten it or adjust it, and you don’t bother Google or Yandex search with such queries. The chain in the scooter engine is tensioned automatically. And if it has already stretched to such an extent that it begins to fly off or jump over the teeth, feel free to disassemble the engine and replace it with a new one. There are no miracles.

And I will prove this to you now. The chain in the engine is tensioned using a special tensioner, which operates in a fully automatic mode. As the chain stretches, And the more the chain stretches, the more the rod will come out. But! The rod has a limited stroke: on a completely new chain it comes out about a third of its stroke and then, as it stretches, it comes out completely and then it won’t come out anymore. Therefore, the chain will no longer be tensioned! And all your attempts to correct the situation will lead to nothing.

Source

Valve adjustment on Alpha

I want to touch on an interesting topic that everyone has heard about, but not everyone understands its essence - let's talk about valve adjustment.

A little theory.

First, a little theory. Where did the need to adjust the valves come from and why is the thermal gap needed?

Any four-stroke engine has at least two valves: an intake valve, through which the working mixture enters the combustion chamber, and an exhaust valve, through which exhaust gases exit. Part of the valve is constantly located in the combustion chamber and therefore the valve becomes very hot. And as we know from school physics courses, bodies expand when heated. Moreover, the stronger the heating, the greater the expansion.

The valves in the engine are always in a “spring-loaded” state, while the valve plate is pressed very tightly to its seat - the valve seat. This ensures that the valve closes tightly.

To open the valve, you need to press on it. In our case, the valve is pressed by a rocker arm, which moves under the influence of the camshaft cam.

Now let’s imagine that the engine is cold (it stood for several hours and all the parts cooled down to “room” temperature). If you start the engine, the valves will begin to heat up quickly and, as a result, lengthen. If you do not leave it room for expansion (the gap between the rocker arm and the valve stem), then the moment will come when the valve will elongate so much that it will not fit tightly to its seat and will begin to leak gases from the combustion chamber. This leads to a loss of engine power and can also lead to overheating and burnt valves.

IMPORTANT: the gaps are set on a cold engine , when the valve has not yet had time to lengthen.

What happens if the valves are adjusted incorrectly?

Very often on various forums questions are asked: “What will happen if the valves are adjusted incorrectly?” There are two possible options:

Thus, too little clearance is much more dangerous than too much. It is for this reason that it is not recommended to set gaps “by ear” without feeler gauges. If there is a feeler gauge between the rocker arm and the valve, there will already be a gap between the rocker arm and the valve, unless of course you clamp it with great force.

Why combine tags?

The valves must be adjusted in a position where the rocker arm does not press on the valve stem, that is, the valve is closed. When a four-stroke engine is running, both valves are closed at the end of the compression stroke, so for ease of adjustment, align the mark on the camshaft sprocket with the mark on the head housing. This position corresponds to the top dead center - the end of the “compression” stroke and the beginning of the “power stroke” and both valves are closed at this moment and can be adjusted.

By and large, it is not necessary to clearly combine these marks, because both valves close already at the beginning of the compression stroke and do not open until almost the end of the power stroke, that is, the valves are closed at least half a revolution. That is, there is nothing to worry about if you “overshoot” the mark a little, or if you don’t reach it a little (within reasonable limits, of course).

For some reason, some “craftsmen” in their video instructions combine the “T” mark on the crankshaft flywheel. It is not necessary to do this to adjust the valves. For one revolution of the camshaft, the crankshaft makes two revolutions, and the mark will coincide twice: once at the end of the compression stroke, and the second time at the end of the exhaust stroke (when the exhaust valve is still open and the intake valve is preparing to open).

What should the valve clearance be on an Alpha?

The intake valve clearance on most engines is usually less than the exhaust valve clearance. This is due to the fact that the intake valves heat up less. They are cooled by fresh air flows.

The thermal clearance of the intake valve for the 139FMB engine is 0.03 mm. For the exhaust valve, the gap is 0.05 mm.

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Hall Sensor Rotor

Commutator Ignition Coils

The whole system is connected approximately as in this diagram

It differs from the real one in that:

there are no SB1 and SB2 in the circuit, coil L2 - the Hall sensor is located on the outside of the rotor,

There is also a magnet there, which is the ignition signal.

The picture shows a Hall sensor and two coils, which are a generator.

The switch is shown schematically and has five wires.

White - common wire or ground. Red and black - charger inputs

voltage. Yellow (less often - green) - control input.

Blue - output to the ignition coil (there may be a different color scheme).

How it works.

When cranking the crankshaft with a manual or electric starter

The rotor with magnets begins to rotate.

The rotor magnets create a changing magnetic field that crosses

turns of the coils and creates an alternating voltage at their terminals.

The voltage generated by the charging coil L1 is supplied to the rectifier bridge

switch assembled on diodes VD1...VD4.

The rectified voltage, through the diode VD5 and the primary winding T1, charges

storage capacitor C1.

The output controlled by the Hall sensor is connected to the control electrode

The voltage controlled by the Hall sensor is shifted in time relative to

voltage L1 so that C1 is charged first and only after that the control electrode

The thyristor receives a control pulse.

The thyristor opens, the capacitor voltage is applied to the primary winding T1

(the VD5 diode is turned back on and does not interfere),

As a result, a spark occurs in the spark plug.

The capacitor is discharged, releasing the accumulated energy to the spark.

After the capacitor is discharged, all processes are repeated again, the engine starts and starts working.

Theory about ignition control.

1. Move the Hall sensor as shown in the picture, thereby slightly advancing the moment

meeting the magnet with the sensor.

2. Sharpen the steps.

All mopeds from the store usually have late ignition from the factory,

hence the carbon deposits on the spark plug and the sluggish response to the accelerator handle, perhaps

The quality of domestic fuel plays a role.

Source