First, Judge fault tips, and several kinds of cleaning methods
1. The normal operation of engine, the accelerator suddenly increased automatically, flame-out after several seconds.This phenomenon for the oil plug, gasoline burning, as long as eliminate oil plug, can return to normal.
2. Gasoline engine start is difficult, need to pull start round several times in order to start time, and automatically shut down after running for a period of time.This phenomenon more for ignition coil insulation caused minor damage, use multimeter to measure, as long as the replacement of the ignition coil, fault or be ruled out.
3. Turn the start by hand wheel, can hear the high-pressure fire, but the spark plug without fire.This phenomenon for the ignition coil loose solder, the solder joint fire, just put the solder joints welded again can.
4. Several kinds of cleaning methods.Oil cleaning method: (1) use of overdue oil gas or there is a small amount of hot water washing detergent with clean parts should be dry and then assembled.Spark plug (2) the carbon deposition and oil removal methods: inside and outside the spark plug with wire electrode carbon deposition in the ring groove all, into the boiling water for 5 min, again with old tooth brush as electrodes, carbon deposition and oil to dry completely before use.By this method the spark plug can be repeatedly used for a long time.Carbon deposition (3) the muffler and oil removal method: put the silencer on the fire to burn to no soot emitted, reoccupy after cooling fine wire shave their carbon muffler.Also in the muffler injection gasoline or kerosene, smoke mouths are forcibly shake, carbon deposition and pollution is put to the best of the oil after dissolving, the stay in the muffler residual oil volatilization completely before use.
Second, the small gasoline engine disassembling matters needing attention
1. The machine most parts of aluminum alloy, fasteners, when loading shoulds not be too tight, in case of damage of shiu wing.
2. Remove the piston, first remove the ring, piston pin and piston under the oil heated to about 160 ℃, the piston pin can be gently.Piston installation has certain direction, at the top of the arrow points to vent.
3. Remove the piston ring, do not make open open is too big, lest produce deformation or fracture.
4. Installation of cylinder block, piston ring incision should be aimed at the location in the ring grooves pin, then put into cylinder, piston cylinder inlet pipe end and crank case high tension line lead to gaps in the same direction.
5. Magneto flywheel drawing and cooling fan must use the disassembly, magneto flywheel mount after, must check woodruff key match quality, at the same time check whether in the keyway.
6. Before and after the piston, connecting rod, crankshaft movement parts into half a crankcase, before and after half a crankcase must be placed in the oil heated to 170 ℃, and keep 3 min, take out immediately after pressure into the moving parts on the right ball bearing.After loading first half crank case, after the first half of the crankcase.
7. Crankcase generally are not allowed to remove, if must remove, half crankcase faying surface before and after the installation, must be coated with insulating varnish, to keep the seal.
8. It is forbidden to remove the heat engine.
Third, the gasoline engine to use for a long time, power is insufficient, rotational speed came to repair
Gas path, poor in piston ring cylinder compression force is given priority to;Oil, generally require cleaning;Circuit, to the spark plug, ignition coil, relay, capacitor for inspection, and adjustment.
Before starting to get off silencer, cylinder vent place of carbon should be removed, and check whether the silencer is blocked.Check whether the carburetor oil needle adjustment is normal, whether the oil level is too low, otherwise it will cause lack of power, speed couldn't get on.If according to the method of repair is still bad, should check whether the crankcase oil seal oil leakage, leakage.Inspection etc. Remove the cylinder body first, with a clean gasoline into the crankcase, a piston in one hand and rotate the crankshaft with another hand, see the oil seal and the crankshaft joint gas leakage, if any, that oil seal wear and need replacement.
Four, gasoline engine running, spray carburetor down serious repair
First check whether the silencer is clogged, cylinder vent place for carbon deposition, because of the poor exhaust, the volume is reduced.Followed by the piston ring and cylinder wear to produce gas, decrease negative pressure in the crankcase, mixture of carburetor throat area can not be inhaled, department of mixture from the suction pipes, the cause of the phenomenon of the spray.Repair, muffler, cylinder vent shall be rid of carbon deposition, the wear of piston ring and cylinder should be replaced.
Gasoline engine running, the carburetor kept the spill, and in fact is not the phenomenon of the spray, but a carburetor needle valve failure, oil cannot be closed, due to the fuel tank is higher than the carburetor, make the oil float chamber too full, overflow from the carburetor ventilation holes.Repair, mainly out of needle valve failure.Remove the float chamber press two needle valve stents and float contact presser foot, needle valve will travel up and down to about 1.5 ~ 2 mm, if the journey is too great, the needle valve stent elbow and pin connection part, with the needle nose pliers to bend, whereas bending outward.In addition to check whether the float oil spill, if there is a burr hole, when float up to the highest position, the plane can't touch rod.Finally, do the leak test, through to oil, when the needle valve down, fuel oil can flow smoothly, the needle valve lift up, can close the oil.