1. Oil road problem
After the mixture is diluted, the gas ACTS on the piston thrust is insufficient, and the combustion time is prolonged, and the engine is overheated. The reason of distinguishing lean oil is that the speed is not good in work, when the air door or oil is pumped by hand, the speed is improved, and when the mixture is not enriched, the speed is weak.
At this time we can say that the motorcycle is in a state of low oil. There are many reasons for the poor oil, the first can be divided into the following points
(1) carburetor reason: main oil needle adjustment: too low; Too low oil level adjustment; The main orifice is partially blocked; Carburetor interface loose leakage; Air filter not installed; The fuel switch in the tank is not working well.
(2) poor sealing of crankcase of two-stroke engine: oil seal failure and leakage of crankshaft on one side of generator; The joint surface of the crankcase is leaking; The joint surface between the crankcase and the cylinder is leaking or the piston device is in the wrong direction (not assembled according to the symbol, mainly refers to the two-punch car).
(3) causes of reed valve of two-stroke engine: damage of reed valve; The rotary valve is mounted backwards, causing the carburetor to blow back.
2. Too much oil
Too much mixture causes the motorcycle to accelerate slowly. Due to the shortage of enough oxygen when the mixture is over concentrated incineration burst, the mixture incineration is not complete, the power is reduced and the economic function is poor, which is prone to the occurrence of many carbon deposition blocking exhaust equipment, and the phenomenon of accelerated impotence is even more.
It can be found that the spark plug is easy to be immersed in oil and the carbon black accumulates on the main surface. Moreover, fuel consumption is over, but slight oil abundance has little effect on high-speed operation, and the closed air door in operation will aggravate the problem. There are many reasons for rich oil, the first should be from the following aspects:
(1) whether the air filter is blocked; Carburetor plane too high; Carburetor float chamber overflow; Carburetor main hole loose; The carburetor thickening system is not reset properly. Main air flow hole of carburetor is blocked.
(2) poor fuel quality: gasoline label is wrong, can cause deflagration; Gasoline storage over time, decomposition, calorific value decreased; There is water in the oil to make the engine operation is not connected and show shooting phenomenon, there are other components in gasoline.
High pressure spark in bad condition
High voltage power off, because the incineration system of high and low pressure components and lines so zhang can cause high pressure jump fire is not connected, causing the engine smell rest operation to speed up the weak; High voltage spark red, weak, due to incineration circuit electrical components and circuit fault caused by high voltage too weak, so that the engine operation is poor.
Causes the high pressure spark bad primary reason has the following points, in the actual repair should be noted; View the following items:
(1) the spark plug operation is bad and the salt gap is wrong;
(2) leakage of high voltage wire and hat;
(3) leakage of electricity in the high-voltage coil and moisture inside;
(4) ignition problems;
(5) the charging coil and trigger coil are not working well;
(6) wrong gap of platinum and bad operation; (there are few platinum cars nowadays.)
(7) capacitor damage and bad tie;
(8) poor contact of low-voltage incineration line;
(9) rotor cleaning and boring of magneto;
(10) there are many magnetic particles adsorbed on the surface of the trigger coil.
The ignition was too early
High pressure spark incineration occurs too early in the incineration time, which brings great resistance to the piston which is rising and contracting. It not only affects the acceleration function.
And will lead to the engine is not easy to start, idle poor and speed up the phenomenon of knocking cylinder. The reasons for premature burning are as follows:
(1) too large gap in platinum;
(2) improper adjustment of the distribution board;
(3) rotor roll key of magneto.
The ignition was too late
The burning time is too late because the burning time missed the best burst time, and make the flame in the cylinder of the time to stay long, not only directly affect the speed up the function, but also can cause engine overheating, exhaust pipe blasting, sound boring and other phenomena. The reasons for the late burning are as follows:
(1) the gap of platinum is too small;
(2) improper adjustment of the distribution board;
(3) poor operation of incineration equipment in advance;
(4) rotor roll key of magneto.
Car body walking part of the work of bad inertia problems are the first: after the stalled neutral, the operator to promote the vehicle found that the resistance is very big, motorcycle in the work to consume a lot of power, must cause to accelerate the weak. The primary reasons for poor walking inertia are as follows:
(1) insufficient tire pressure;
(2) the front and rear braking equipment is malpositioned;
(3) the front and rear wheels are not in a straight line;
(4) the wheel bearing is too tight (if the center bush is not added, the inner wheel bearing backup cap will be locked automatically during wheel rotation;
(5) the transmission chain or belt is too tight;
(6) tire friction car body or car * part.
4. Other reasons
1, piston ring wear severe, beyond the operating limit;
2, piston skirt wear severe, beyond the limit of use;
3, cylinder inner wall wear severe, beyond the operating limit;
4, cylinder liner leakage;
5, crankshaft oil seal leakage;
6, the cylinder body carbon serious, carbon stick dead piston ring;
7. The exhaust port, exhaust pipe or muffler are blocked by carbon deposition;
8, dust covered or blocked air filter;
9, burning time too early or too late;
10. The contact of the broken electrical appliance is severely ablated, slightly worn, loose or broken;
11. Capacitor damage;
12. Leakage of high voltage coil or wire;
13. Spark plug type is not suitable and carbon is connected between electrodes;
14, carburetor lean or rich oil;
15. Clutch slip;
16, gasoline decay, label is wrong, octane number is too low;
17. Too much oil in the mixed oil (mixed smooth engine);
18, the brake shoe block is not back;
19. Loose transmission belt;
20. Lack of tire pressure;
21, reed valve damage (reed valve intake mode engine);
Loose valve closing (four-stroke engine);
23, single cylinder operation (more than two cylinder engine);
24, long time low or high speed driving, resulting in engine overheating;
25, people or load is too heavy, beyond the additional load