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!
High gear limiter (“H”)
The high gear limiter prevents the chain from jumping off the smallest sprocket and getting stuck in the middle of the dropout and it. And, although the index shifters perform the same function by tensioning the cable - preventing the chain from jumping off the smallest sprocket, but, correctly, regularly, and according to science, this should be done by the limiting screw. Cables sometimes break, you know.
We configure the high gear limiter as follows: 1. switch: the largest sprocket in the front and the smallest in the rear; 2. loosen the shift cable. This can be done by unscrewing the bolt holding the cable in the transfer area. Or you can screw in the adjusting drums on the shifter and shifter as much as possible. (I almost never use this. I set it so that their state is always screwed in.) 3. We set it so that the switch rollers lie in the same plane as the smallest sprocket. See picture. 4. Upon completion of the adjustment, you need to strongly pull the cable and clamp it on the transfer. Or, unscrew the adjusting drums if you were able to loosen the cable in this way.
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.
When and why to check the circuit
Manufacturers recommend checking every 1,000 kilometers. Under intense loads, if you have to travel hundreds of kilometers per day, inspection is required much more often. But by installing a high-quality chain, the motorcyclist will be able to reduce the number of checks.
Just by looking at the moped from the outside, it is not difficult for a specialist to determine if the chain is not tensioned correctly. Such an error when servicing a moped can lead to a break in the chain during a trip. Over-tightening occurs quite often and, despite the presence of lubrication, leads to accelerated wear of the chain. As a result, the suspension begins to work incorrectly. Over time, the hub may fail.
A poorly tensioned chain also often causes breakdowns. When moving, it will fluctuate greatly, and as a result, difficulties will arise with switching speeds. The shock load on the gearbox gears and rear hub will increase. The chain can lock the wheel axle by wrapping around it. Such a breakdown can lead to a serious accident.
The transmission of torque from the motor to the rear wheel in Alpha mopeds is carried out through a chain drive. This mechanism uses two stars connected by a chain. The first sprocket is connected to the gearbox, the second to the rear wheel.
The degree of tension changes as the pendulum moves along an arcuate path by the length of the suspension stroke. When stretching, it is important to remember that there should be a margin of 2-3 centimeters in length. Maximum tension is achieved when the following elements are lined up:
- pendulum axis;
- secondary shaft;
- wheel axle.
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
We adjust the position of the switch above the stars.
Now we connect the gear shift cable in place. We tighten the cable length adjustment nut (located between the jacket and the shifter) on the switch until it stops, and we also screw the adjustment nut on the shifter (on the steering wheel, located between the jacket and the shifter) until it stops. We simply tension the cable and secure it with a hexagon bolt.
Then we click the shifter two (let’s say) times - as a result, the roller should be (in mind) above the third star. But, most likely, you will have something like the photo below
As soon as you accurately position the video above one of the stars, it will automatically move accurately between other stars.
The exception happens if the switch itself is very worn out (behaved, skewed, the cock between the switch and the frame may be bent) - then you will have to look for something in between. So that it hits more or less below, and above.
After that, we put the chain back on - spin the pedals (is the bike still upside down?), click the switch back and forth, spin the pedals, click again, and enjoy the sight of the chain running across the cassette. You can do this for another 10-15 minutes without getting bored
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.
Preparatory work
It is imperative to clean the chain, otherwise tensioning will not work. There is grease on metal surfaces, and dust accumulates on top over time. These contaminants cannot be washed off in ordinary water; you need to use auto chemicals. It is better to choose a product in the form of an aerosol that will not corrode the seals - chain O-rings
If the mechanism is heavily dirty, it is advisable to remove the cover from the drive sprocket. It is important to ensure that the retaining nut is well tightened. The cleaning itself is carried out as follows:
- First, rotate the moped wheel while spraying the cleaning composition.
- The mechanism is left for several minutes so that the product is well absorbed into all the recesses.
- Using a stiff brush, remove dirt from the sprockets and chain.
- Use a clean cloth to wipe all parts of the mechanism.
Cleaning a moped chain
Now you need to determine the degree of wear of the elements. The chain links should not jam, ideally they move easily. It is also necessary to check the presence and condition of the seals. The sprocket teeth must not be bent, pointed or damaged. Wear on the tooth surfaces may be associated with improper installation of the rear wheel.
To determine the condition of the chain, you need to check whether there are areas where the tension is too high or, conversely, weak. To do this, you need to manually turn the wheel. If such areas are present, it means that the bushings and pins have worn unevenly. In this case, the distance between the pins increases and the chain becomes longer.
Severely worn chain
Often the cause of the appearance of sections with different tensions are problems with other components of the moped. The sprockets may be installed with an incorrectly centered hole or the wrong diameter. Uneven tension may be due to severe wear on the wheel hub or failure of the sprocket hub bearings. But other damage may also be discovered, so it is important to carry out a thorough inspection.
It is easy to determine the degree of wear by the length of the chain. To do this you need to pull it back. It is important to try to pull the chain off the sprocket at the same time. Replacement is required when, when attempting to remove, most of the sprocket tooth becomes visible. If the chain rollers are bent and squeak when driving, it is better to change the part along with the sprockets.
After cleaning, you need to align the rear wheel. This is an easy task if the axis is marked. But the marks sometimes get confused, so additional checking is necessary. As the rear wheel rotates, you need to shine a flashlight and pay attention to the chain. If it does not move straight, it means the installation was not done correctly.
After installing the rear wheel, you need to remember where the marks are located. If they are not symmetrical, this indicates that the marks were applied incorrectly. In this case, you can draw new marks on the reverse side of the chain with a marker. When tightening the rear axle, it is important to push the wrench toward the front wheel.
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.
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.
other methods
There are a lot of ways to make a bicycle chain tensioner with your own hands from scrap materials. To do this you will need a small sprocket and a fastener. The fastening can be a clamp from a flashlight on the steering wheel, a cut-out aluminum leg in which holes are drilled for attaching the sprocket and bolts that will press it to the frame. Some craftsmen even make fastenings from an ordinary plastic cutting board. The main thing is imagination.
The tensioner is usually attached to the chainstay
It is important to take into account that you need to tighten the chain from the bottom (preferably from the bottom up). After all, the upper part is always tense when pedaling
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.
Professional approach
Many motorcyclists treat chain tensioning as a routine procedure, during which significant tolerances can be made and the position of the rear wheel can be adjusted “by eye”. This approach when setting the required chain tension is unacceptable - all operations must be performed as carefully and accurately as possible, using special tools. If you want to extend the life of the chain and avoid severe wear on the transmission when using the motorcycle in extreme conditions, you should purchase a special laser gauge to set the optimal wheel position. In the most difficult cases, if you cannot understand the structure of the adjusting mechanism or cannot loosen it, you should contact the specialists of a motorcycle service station. They will carry out all the necessary work, providing you with a guarantee of the quality of the result and the reliability of the motorcycle.
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.
Additional actions
If you know how to tighten a motorcycle chain, it wouldn't hurt to check the condition of the sprockets and other transmission parts. If signs of significant wear are detected, they should be replaced immediately, since breakdowns of this type seriously affect the reliability and durability of the motorcycle transmission. If you find that the chain is very stretched, it is better to get rid of it immediately - especially if you like to ride at high speed or perform stunts by tipping the motorcycle onto its rear wheel.
In addition, when regularly tightening the chain, it should also be cleaned and lubricated. It is better to use special products in cans that are supplied under high pressure - they effectively wash away all foreign deposits and also penetrate into all internal parts of the chain drive, contributing to its effective lubrication. The procedures are also performed with the rear of the motorcycle raised, which allows you to quickly spin the wheel if necessary. There are also special devices for cleaning the chain. The device is fixed to the transmission mechanism of the vehicle, after which all that remains is to engage first gear and ensure a continuous supply of cleaning agent to the receiving tube.
The motorcycle is serviced approximately every 500–2000 kilometers, which ensures the reliability and durability of all mechanisms. Every time you clean and lubricate, you should check the degree of chain tension to prevent serious sagging. Experts say that on average, tensioning has to be done every 2–5 thousand kilometers, depending on the operating conditions of the motorcycle. It is worth completely changing the chain every 10–15 thousand kilometers, or more often with an aggressive driving style or with frequent off-road trips. Failure to comply with these deadlines leads to accelerated wear of the transmission and the approach of expensive motorcycle repairs.
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.
Road switches
Shimano also makes SORA and TIAGRA road derailleurs. Speaking of switches, it is also worth touching on the shifters (shifters located on the steering wheel). Children's and budget bicycles are often equipped with revolving-type shifters, which can be switched by simply turning them like the throttle on a motorcycle. The advantage of such shifters is that they are inexpensive and you can quickly switch to several gears with one rotation of the wrist.
The downside is that it is difficult to switch to a specific gear, and there is a possibility of accidentally switching by carelessly holding the steering wheel. Therefore, the most common are trigger shifters.
Changing gears with such shifters is very easy. The two levers are under the index finger and thumb on Shimano, and both under the thumb on Sram. Once you ride a bike with such a shift system, you will immediately remember which lever downshifts and which upshifts. In addition, on road bicycles there are switches on the frame, as well as those combined with the brake handle.
