Do-it-yourself Lawnmowers Repair. Lawn mowing construction

DIY lawnmowers 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:

  1. Move the choke lever to the open position. Position the trimmer on its side so that the air filter is on top.
  2. Hold or lock the throttle in the on position (the throttle must be held until the engine warms up).
  3. If the device has an on / off switch, move it to the on position (usually indicated by “I” rather than “O”).
  4. 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.
  5. 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.
  6. After starting the engine, keep the start button pressed and let it warm up for 10 seconds, then turn off the start system.
  7. When the lawn mower warms up, it must restart with the throttle in the closed position.

Lawn mowing rod repair. 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.

Do-it-yourself Lawnmowers Repair. Lawn mowing construction

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

Video: Do-it-yourself Lawnmowers Repair. Lawn mowing construction


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.

Dismantling lawn mowers Stihl. Dismantling Calm.

1. Unscrew the 3 screws securing the starter (item 16), remove the starter. without losing the rubber shock absorbers of the tank.

2. Next, unscrew the 11 screws (p. 4,7,9) securing the plastic housing. Please note that the screws (p. 9 and p. 7) differ from all the others in length. remember the places of their fastening)

The screws for attaching the engine to the plastic case also differ (they are engraved on the inner hat)

3. Then remove the upper part of the crankcase (item 2), disconnect the 2 terminals from the ignition module (mark the seating of the terminals on the module so as not to confuse them during assembly).

4. Dismantle the air filter cover (item 8), the air filter (item 1). Unscrew the 2 nuts (item 7) of the rear housing (item 2). We remove the gasket (item 20). Disconnect the fuel tank hoses (item 3) from the carburetor.

Repair of Chinese lawn mowers. Replacing the CPG on Chinese lawn mowers

Hello everyone! Today we will consider replacing the cylinder piston group lawn mowers Maxcut MC158 and similar Chinese lawn mowers. There are a very large number of lawn mowing models, but almost all of them have the same replacement of 2-stroke cylinder pulses. Initially, they brought a scythe with complaints that the engine does not start, due to the extensive experience in repairing such braids, I pull the starter handle and notice that the piston goes without resistance, that is, there is no compression.

We remove the muffler by unscrewing the two main bolts and one additional bolt at the bottom of the muffler.

I look in the cylinder and see a typical picture of overheating, as a result of which the rings burst, tearing the piston and cylinder. Chinese braids are very tender, do not like a little oil and long work, which is why this breakdown occurred.

Then everything is in order to get to the piston. remove the cooling casing and the carburetor.

We unscrew the 4 screws of the cylinder and pull the cylinder up, it may require effort, since the gasket may stick to heat.

We see a dead piston and a cylinder in badass.

Then we put a new piston, finger, piston rings, retaining rings, a new gasket, a drop of oil on the rings and put on the cylinder. Tighten all screws and all operations in reverse order. We start the braid, adjust the carburetor if necessary. At this repair is over, the repair time is 30 minutes, you can get rid of weeds further.