Do-it-yourself Champion Lawn Repair. Lawn mowing construction
Do-it-yourself Champion lawn repair. Lawn mowing construction
The trimmer consists of three parts: a gasoline engine, a rod with a shaft inside and a cutting element. Torque is transmitted through the shaft from the motor to the cutting head. In trimmers with a curved rod, the role of the shaft is played by a cable. The rod itself is attached to the gearbox of a gasoline engine. There is engine control on the bar, a belt can also be attached, for convenient use of the trimmer. The cutting element in lawn mowers is a fishing line wound around a trimmer head or a special knife used to trim large weeds.
The main and most complex unit in the trimmer is the engine. In domestic and semi-professional lawn mowers, two types of engines are used. 2 or 4-stroke. Depending on the type of gasoline engine, its refueling and maintenance are different.
- 2-stroke engines do not have their own lubrication system, so they do not work on pure gasoline, but on a mixture of gasoline and oil. The latter, entering the ignition chamber, lubricates the moving components of the engine.
- 4-stroke engines are lubricated with oil in the crankcase. They work on pure gasoline without impurities.
Do-it-yourself lawn mowing and trimmer maintenance can be done without outside help. If replacement of motor spare parts or its adjustment is required, then it is necessary to contact a repair shop.
First launch at the beginning of the season
In late spring, when the active use of lawn mowers begins, before starting work, you need to do an inspection and a test for the performance of your tool. Be sure to lubricate the rotating parts, inspect and, if necessary, replace the cutting elements (knife or fishing line). Check for fuel mixture in the tank. If you drained fuel at the end of the previous season, do not forget to pump fuel into the engine using a suction (if it is in the engine).
If this is your first time using a trimmer, be sure to read the instruction manual. Such instructions should be attached to each lawn mowing ground.
Starting most two-stroke engines is quite simple. Use the procedure described in your trimmer instructions if it differs from the following:
- Move the choke lever to the open position. Position the trimmer on its side so that the air filter is on top.
- Hold or lock the throttle in the on position (the throttle must be held until the engine warms up).
- If the device has an on / off switch, move it to the on position (usually indicated by “I” rather than “O”).
- Make sharp, quick jerks with the starter handle until you hear the engine try to start. This should occur between 1-6 jerks, but no more.
- Close the throttle halfway and restart the starter. The engine should start after 2-6 additional jerks. If not, move the throttle lever to the full position and pull the starter handle again. Return the lever to half the throttle and pull another 3 times.
- After starting the engine, keep the start button pressed and let it warm up for 10 seconds, then turn off the start system.
- When the lawn mower warms up, it must restart with the throttle in the closed position.
Champion trimmer carburetor adjustment. The device and carburetor adjustment on lawn mowers and trimmers
Lawn mowing or trimmer with internal combustion engine require not only constant refueling of the fuel mixture of gasoline with oil, but also periodic adjustment of the supply of this fuel. The carburetor is responsible for supplying fuel to the lawn mowing cylinder, the efficiency and productivity of the tool depend on the proper operation of which. If a malfunctioning (abnormal) engine operation is detected during operation, the first thing to do is adjust the carburetor of the lawn mowing machine. Before setting up the carburetor of the gas trimmer, we will first deal with its design.
Design of a petrol-trimmer carburetor and its purpose
Lawn mowers are equipped with push-pull type internal combustion engines. To feed the air-fuel mixture into the engine cylinder, a carburetor is used. In the design of gasoline units. This is a key element without which the operation of the internal combustion engine is impossible. Over, this carburetor differs from the automobile device not only in size, but also in the principle of operation. In particular, this difference lies in the presence of a membrane, which plays the role of a gasoline pump. It is due to the presence of the membrane that the devices under consideration in the design of two-stroke internal combustion engines are called membrane.
Structurally, the entire mechanism is a small-sized part, inside of which there are channels, valves and membranes. The carburetor body is made of aluminum, and the internal device is shown in the photo below.
Repair starter lawn mowers. Starters for lawn mowing: device and installation features
Manual starter for lawn mowing or gas trimmer. A mechanical unit that includes a pulley mounted on a ratchet. A rope is wound on the pulley in the initial position. At start, it is pulled out. The pulley is spring-loaded. If you let go of the end of the rope, it will wind back. A flat ribbon rolled into a ring is used as a spring. It resembles a spring in a large mechanical watch that starts once a day. The starter itself is located more often on the back than closer to the front end of the mower or trimmer. In order to correctly perform all manipulations with the starter for lawn mowing, you need to know the features of the device and installation.
How is the starter or trimmer starter arranged?
Starter. The mechanism as a whole is single and universal for lawn mowers, trimmers, gasoline and diesel generator sets. It’s not a problem to equip them even with a car, motorcycle or scooter if your vehicle has free space for installation. Not for nothing that many Soviet cars and trucks were equipped with starter tools, which vaguely resemble a double-bent mount.
The modern “handbrake” starts up from the cord. It is tied to the mechanism, and it is impossible to lose.
The starter assembly has the following parts:
- Hook spring;
- Cord wound around a reel;
- Return spring;
- Drive ratchet and main spring;
- Ratchet mechanism housing;
- Locking bolt.
Worst case breakdown
There are times when the starter is still operational, but, for example, a worn cord may break. The ratchet has not yet had time to work when the engine starts, and the rest of the cord is immediately wound on a reel, the return spring loses hooks, the grooves in the starter housing break. The result is the replacement of both the springs and the housing.
If the model of lawn mowers or trimmers has long been discontinued, it will be difficult to find exactly the same parts, and the starter changes completely.
How to replace or replace the starter spring?
If everything was okay with the rope on the starter, suspicion falls on the coil itself. It is driven by a tape spring rolled up into a roll. To change the spring, certain steps should be taken.
- Remove the starter from the lawn mowers.
- Remove the starter coil.
- Unscrew the main bolt holding the pulley on the housing.
- Pull out the gripping antennae and spring, the band spring is almost completely straightened or folded with larger diameter rings.
- Hold it in advance.
- Check if the spring is intact (there may be rusty stains, breaks, etc.). If the hooks at its ends are broken, it will not be possible to bend new ones. High-carbon steel breaks when trying to bend it. Weakened hooks are suitable for easy bending.
- Make sure that the auxiliary spring with washers is in place. These parts protect the coil frame from being pierced by the ends of the main spring. If the washers and the spring break, but there are no new ones, do not tighten the coil bolt tightly, but watch for it. It may loosen and get lost.
- If the main (flat) spring is damaged, insert the same new one. Put the hooking hook at the end of the spring in its place and bend it, inserting coil by coil into the space where it should be.
Spring rewinding takes one minute. Dexterity in this action is fast.
The lawn mowing will not start. Why the lawn mowing and trimmer do not start, possible causes and solutions
If the trimmer or lawn mowing does not start, then any desire to mow the grass disappears. Very often, the owners of these tools encounter difficulties starting a two-stroke or four-stroke engine after winter, when the tool has not been used for a long time. If this situation occurs, then do not rush to hand over the tool for repair. Start troubleshooting from less to more, and with a 100% chance you will be able to start the gas trimmer engine. Where to start troubleshooting, when the lawn mowing does not start, we will consider step by step with all the details.
Trimmer does not start. Which nodes need to be checked
To start gas trimmers, manual starters are used. By means of such starters, the crankshaft is manually moved. In this case, it is important to turn on the ignition, so that when the crankshaft rotates, the fuel-air mixture entering the cylinder can ignite. Ignition of the first portion of the mixture will entail starting the engine, and the trimmer is ready for use.
However, it often happens that attempts to start the engine are nullified. Naturally, when after 5 attempts to start the engine, it is not possible to achieve success, then you need to proceed to diagnostic measures. There is a special sequence that should be followed in order to find the reason why the lawn mowing does not start, and successfully eliminate it. The verification sequence has the following format:
- Check for fuel in the tank and the quality of the mixture of gasoline and oil
- Determine the color of the spark plug, as well as signs of its functioning
- Make sure the air filter is working.
- Check the fuel filter, which is responsible for cleaning gasoline with oil entering the carburetor
- Service breather
- The reason that the lawn mowing does not start may be the exhaust duct or silencer
It is these nodes that are the main sources of the problem of the difficult start of the trimmer. A more difficult problem is the malfunction of the carburetor, which needs adjustment. Consider each node individually to find out the reasons for which the trimmer does not start, and eliminate them with your own hands.
The first step is to check fuel availability and quality.
You do not understand why the lawn mowing does not start, then first make sure that there is fuel in the tank. Often, beginners forget that it is necessary to pause periodically in order to fill the tool with a gasoline-oil mixture. If the lawn mowing tank is empty, then naturally it will not start, no matter how much you try to do it.
DIY lawn mowing drawings. Primary diagnosis of the trimmer.
The proper operation of the engine and lawn mowers as a whole is influenced by a huge number of factors that are usually related. If you are unable to determine the malfunction, contact a trusted service center.
I would like to note that before proceeding with disassembly and serious repair, you should check basic supplies. These “little things” often affect the work and, perhaps, repairing the trimmer will cost, so to speak, “little blood.”
Spark plug. No carbon deposits, electrode gap (0.5-0.6 mm. Or as per instructions), good spark
Fuel filter. No pollution, mechanical damage, good throughput. Periodic replacement according to the maintenance schedule in the operating instructions
Air filter. No sawdust or dirt. Periodic cleaning in soapy water and high pressure purging. Replacing the air element according to the operating instructions
Let’s get acquainted with other possible malfunctions:
1. Air leaks into the engine
It is worth noting that many owners confuse air leaks with carburetor malfunctions. Symptoms of air suction in the engine. A strong overspeed, both short-term and constant. Or the scythe simply refuses to start.
The main causes of air leaks on the Chinese trimmer:
- Allows crankshaft oil seal (12227mm small). From starter side
- Misses crankshaft oil seal (15307mm large). From the flywheel
- Carburetor gasket wear
- Crack on carburetor adapter
Actually, it is possible to understand what exactly from this list caused air leaks on a gas mower only by a detailed inspection. To unscrew, remove and suffer in any case, so then in order.
Replacing oil seals of the Chinese trimmer.
One of the main reasons for air leakage into the engine are crankshaft oil seals. In general, this problem is the most common on Chinese trimmers and, in some cases, oil seals begin to pass air in the first year of service. The blame for the poor-quality rubber products of such mowers, well, and no one canceled the natural wear and tear.
Glands of different sizes are installed on both sides of the crankshaft (12227mm small and 15307mm large). On oil seals, you can safely sin if he begins to “snotty.” Another indicator of their malfunction is floating speed when working on a “hot” one. Next, we consider in detail the replacement process.
Replacing the seal of the Chinese trimmer on the starter side:
We unscrew the spark plug, block the movement of the piston with a stopper. Remove the starter (p.31). Turn off the starter ratchet with a 13mm head (p. 35). Traces of the gas mixture on the oil seal indicate its necessary replacement. Using a thin flat-head screwdriver (with an awl, or any similar object that is at hand), we remove the old oil seal (item 36), pry it with a screwdriver on the crankshaft side and remove it.
Before installation, apply a small amount of oil to the inner surface of the new oil seal (you can use the oil that we use to prepare the gas mixture)
We purge and degrease the seat under the oil seal, evenly install a new oil seal.
Replacing the gasoline trimmer gland on the flywheel side:
We unscrew the spark plug, block the movement of the piston with a stopper.
For convenience, remove the crankcase cover (p. 58) by unscrewing 4 screws (p. 61)
Unscrew the 2 screws securing the clutch (p. 57) with the washers (p. 56), remove the clutch assembly and the washers under it (p. 53)
Unscrew the flywheel nut (p. 52) (p. 51), but not to the end. Not a strong blow to the nut “knock it off the crankshaft.” Unscrew the nut, remove the flywheel and key. We examine the surface of the gland. Traces of moisture, or wet contamination, scuffs and other damage on it are a signal to replace it.
With a thin flat screwdriver (with an awl, or with any similar object that is at hand), we remove the old oil seal (item 50), pry it with a screwdriver on the crankshaft side and remove it.
Before installation, apply a small amount of oil to the inner surface of the new oil seal (you can use the oil that we use to prepare the gas mixture).
Replacing gaskets and carburetor adapter on the Chinese trimmer:
Another cause of air leakage may be the carburetor adapter.