How to Fix a gas trimmer. Lawn mowing construction
How to fix a gas trimmer. 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.
The coil does not spin on the trimmer. Troubleshooting
All the reasons why the lawn mowing does not start can be systematized according to the specifics of the operation of individual nodes. In the service center, the malfunctions are systematized:
- Motor malfunction (piston wear, bearing malfunction, crankcase crack);
- Malfunction. Clogged pores of the air filter or malfunction of the carburetor;
- The ignition system does not work;
- Mechanical failure. Leaking hoses, broken wires under the braid, rupture of tubes.
The user first needs to check if there is fuel in the tank. Start-up is carried out in accordance with the annotation, putting the saw on its side. Set the air damper to the “closed” position, pump up fuel, turn on the ignition and make 3-4 sharp jerks with the starter. If the engine is running, open the air damper. The lawn mowing does not start. We repeat operations with a slightly open air damper.
Lawn mowing cannot work for a long time. The gearbox and engine will overheat. Mowing can be less than 15 = 20 minutes, making a five-minute break. On hot noon, the operating time is halved. When mowing weeds, sedge, the working time is required to be reduced.
If the launch fails, we begin to find the cause of the failure:
- Check fuel quality;
- Make sure the candle is working and the candle channel is clean;
- Check the cleanliness of the air filter;
- Make sure the fuel filter is not clogged;
- Check the purity of the breather;
- Clean the exhaust duct.
Dismantling the trimmer bar. DIY trimmer coil repair
Trimmer Ignition Coil. Faults and Repair
Lawn mowers are a popular seasonal tool designed to remove unnecessary vegetation in the house area. Like any other equipment, these devices periodically break down. Repairing the trimmer ignition coil is one of the most common problems encountered with gasoline braids. The ignition system itself is designed similarly on two- and four-stroke ICEs, so the elimination of breakdown is performed almost the same for tools from different manufacturers, whether it be Lux, Huter, Husqvarna or another brand. Ways to restore the efficiency of the ignition coil or replace it with a new one are in the material below.
Magneto. Design and concept of work
The purpose of the ignition coil is the conversion of rotational energy into a high voltage discharge and the formation of a spark igniting the fuel mixture. In an internal combustion engine, this part is called magneto, since in it an alternating current is generated from the rotation of a constant magnetic rotor or armature.
Magneto constructively consists of two windings: high and low voltage. A capacitor with breaker contacts is connected in parallel to the latter. Whereas the findings of the high voltage winding are connected to the candle and the housing. Both of them are wound on a core, between the poles of which a rotating magnet is installed, magnetized longitudinally.
On a note! The whole design looks like a large coil mounted on a U-shaped core.
Before you start diagnosing magneto, you need to make sure that the problem is actually in this node. To do this, you need to check the entire circuit and make sure that there are no other reasons for the failure of the trimmer.
- First you should carefully inspect the coil for cracks and other external defects on the case. Next, you will need to examine all the elements and nodes that conduct current, and make sure that they are clean.
- The next step is to inspect the high voltage wires. They must be intact and securely attached to the contacts, free of rust and with intact insulation.
- The next step will be to check the candle cap. As a result of careless actions, the user often tears it from the high-voltage wire, and then improvises and creates a makeshift mount. It must be understood that any poor-quality connection in this place significantly reduces the power of the electric arc of the candle.
- Then you need to make sure that the candle itself is working. If you fill the lawn with low quality gasoline, the life of this part is significantly reduced. In addition, it can be flooded or have a large soot that impedes work. Sometimes the candle even sticks and does not unscrew.
- Next, inspect the circuit breaker. On Chinese-made trimmers and chainsaws, it very often breaks.
Do-it-yourself trimmer bar repair. DIY trimmer repair
Lawn mowing repair: how to restore drive shaft gearing
The cause of the trimmer malfunction: “Licked” because the shaft splines at the top are not engaged in their entire length (it happens that the shaft clings only a few millimeters at the end). At the bottom of the gearbox, the shaft enters the entire length under its own weight.
Do-it-yourself trimmer repair the trimmer must be checked and made so that the shaft enters the clutch at the top for the entire length of the splines (or faces, if there is a square). To do this, try to put the gearbox higher on the pipe, having previously loosened its fastening or try to push the pipe deeper into the shock absorber, having previously loosened its fastening. If the shaft splines still do not enter the clutch to the full length, then the pipe must be shortened (cut off part) by the length necessary for the splines to fully enter the clutch.
Warning: Just do not overdo it with cutting the pipe (it is better to cut a smaller piece), since if the shaft is longer and needs to be cut, then when the splines of the shaft are heated, the metal will be released, i.E. Hardened metal will become soft and will not last long (the shaft itself is made of alloy steel).
Lawn mowing works, but does not twist. Where to start diagnosing lawn mowers
If the lawn mowing does not start or immediately stalls after start-up, it is necessary to check all the main components and assemblies in sequence. The verification algorithm is as follows:
- Fuel tank (fuel quality);
- Candle and candle channel;
- Air filter;
- Fuel filter;
- Exhaust channel.
These nodes are most often the source of major problems that can be fixed after a thorough inspection.
Checking the fuel mixture
Before starting the engine of the gas spit, check the availability and quality of the fuel mixture. Do not save, do not be greedy and do not be clever in this matter. Repair or replacement of the piston group will cost you too much (sometimes up to 70% of the cost of a new tool). It is necessary to prepare the oil-fuel mixture strictly according to the instructions. Calculate its quantity from real needs. Excess gasoline remaining after work over time loses its quality.
We diagnose a candle and a candle channel
If the quality of the fuel mixture is not in doubt, and the lawn mower stalls at start-up, then a filled candle may become the cause. Here, for repair, an ordinary candle key (probably every motorist has it) and a spare candle are suitable.
- We twist the candle and wipe it;
- Dry it thoroughly (do not calcine);
- The excess fuel in the chamber is drained through the spark plug hole and dried;
- We clear an old candle from a deposit by means of a file or a lady’s file;
- We set a gap with a distance of 1 mm (you can check with any coin);
- We return everything to its place and try to start a trimmer.
Dry the canal for at least 30-40 minutes. Otherwise, there is a risk of re-pouring a new candle.
If the candle is working, the nest where it is completely dry and the lawn mower does not want to start, we lubricate the threaded connection with gasoline. It should be slightly moistened. No matter how wonderful a spark a candle gives out, there is simply nothing to light up in a dry chamber.
If the trimmer motor still does not start, a cause such as the absence of a spark due to poor contact between the spark plugs and the high-voltage wire should be excluded. If the connection is high-quality, but there is still no spark, most likely, your ignition unit has “flown”. Here you can’t do without a master, because the part is not being repaired, but sold as a single unit.
Diagnostics of lawn mowing filters
Another reason that the gas braid stalls may be an air filter. To exclude it, try to remove the filter and start the trimmer without it. If possible, then you will have to change the air filter to a new one, or at least blow out and thoroughly clean the old one.
A gas trimmer may not start up due to contamination of the fuel filter. This is the next step in our algorithm. Here we check the condition of the filter element and, if necessary, replace it with a new one. When replacing, try not to leave the suction pipe completely without a filter, this is prohibited by any operating instructions. Haste can result in repair of the engine piston group.
Breather and exhaust channel
Often, “gentle” branded lawn mowers do not start and stall due to contamination of the breather. The main function of this element is to equalize the pressure in the gas tank. If this unit becomes clogged, a vacuum is created in the tank, which prevents the fuel supply. You can fix the problem by cleaning the breather. You can use a regular needle for cleaning.
Normal operation of the braids with internal combustion engines may be impaired due to the ingress of dirt into the exhaust channel or clogging of the silencer mesh. There is such a problem on older models. You can solve the problem by traditional cleaning and removal of the anti-spark mesh.