1、 disc brake abnormal sound solution

Reason: If your motorcycle in the pit or vibration when the brake pad hit the iron jingling ring, it must be a disc brake problem.

The solution:

(1) Prepare the hat of the open screw with a word, and turn the 6 angles in the No. 5

(2) Then loosen the brake pad fixing screw with No. 5 inner 6 Angle wrench, and then unscrew the caliper fixing screw.

(3) Take off the brake pad to see the limit shrapnel of the brake pad, this shrapnel is embedded in the caliper, pay attention to the side of the buckle, use the hand to pull out or use the flat lift.

(4) Take out the shrapnel and tilt the curvature of the shrapnel slightly upward with needle-nose pliers.

(5) The curvature of the warp can be large, so that the brake pad will not ring after the big pit or the big vibration.

(6) Then observe the brake pad fixed screw, hand feel smooth, generally long-term brake, screw always a little astringent feeling.

(7) Fine sandpaper slightly polished smooth, coated with butter, and then put into the brake pad, because the arch is large, you have to press the brake pad by hand. (8) Insert the fixing screw of the brake pad. Put it back as is. Finally, butter the screws and tighten them.

(9) After installation, hand pinch and release the brake until it returns to the position.

(10) Test drive, find a pit to ride, to feel the trouble of no ding ding dang it.

2、 The rear brake has abnormal sound

Reason: When the motorcycle steps on the rear brake, the abnormal sound is as harsh as the friction between metals. What is the reason?

Most of the sound is caused by water or dust inside the brake hub, which will not affect the brake, please also note that the asbestos layer on the brake pad is too worn can also lead to this phenomenon, if a long time, it is recommended to replace the brake pad, anyway, safety first, the reason for the sound may be caused by the following problems:

(1) The brake pad quality is not up to standard.

(2) Whether there is a foreign body on the brake device, there will also be noise at this time.

(3) The brake disc or brake pad is deformed, has been impacted by external forces, and many times the eye can not see the subtle deformation, and it will make a harsh sound when in use.

(4) Air humidity to a certain extent will also have a sound, this sound is tolerable. After running for a period of time, the water vapor on the brake pad will not ring or not ring.

(5) This is the asbestos dust produced by brake pad wear between the brake pad and the hub and then the brake pad pressure and temperature form a hard glaze on the brake pad surface, so the brake makes a harsh sound.

Solution: The friction surface of the brake pads with a saw diagonal saw several slots, so that when braking, there is a rotating air flow in the brake drum, and the dust of the brake pads into the groove is swept away by this air flow. You must change the kind of white brake pads, that is hard brake pads, you change a red color of soft brake pads with grooves absolutely no problem.

Suggestion: Brake pads are wearing parts, generally are not guaranteed, unless the quality problems can be replaced, such as the fracture caused by steel fire problems, wear too fast (normal 3 months of wear, a month reached) and so on.

3、 Abnormal engine noise

When the engine is working, the normal sound will be mixed with the abnormal sound, not to mention, the vehicle engine model is diverse, however, as long as the full understanding of the causes of different nature of the engine abnormal sound, familiar with the various nature of the abnormal sound sound parts, characteristics, timing and change rules, pay attention to accumulate experience, It is still possible to accurately judge and determine the nature, location and cause of the abnormal sound.

1, connecting rod big head bearing sound

The reason for the rod head bearing sound produced by the motorcycle connecting rod head bearing sound is usually: The connecting rod shingles (using plain bearings) are not well matched with the crankjournal, the bearings are poorly worn (using rolling bearings), due to poor lubrication, the bushing is too tight and is damaged, the repair operation is improper or the quality of the bushing is not good and the early wear, the bearing ball (column) is worn, and the noise is generated when the engine is working.

Connecting rod big head bearing sound characteristics: The sound does not change with the engine temperature, sudden acceleration (from idle to medium speed), there is a significant continuous percussion sound (rolling bearing accompanied by internal engine noise), which is the main feature of the connecting rod bearing sound, connecting rod big head bearing wear (loose) serious, the engine idle work has a significant sound, increase the load when the sound will intensify, the engine flamed out, The sound weakens or disappears significantly.

2, the valve spring knocking sound

The cause of the valve tapping sound is usually: Valve clearance is too large and CAM wear, the profile curve changes, the valve spring is broken, the engine is working, broken valve springs impact each other to produce sound, valve spring percussion sound is characterized by continuous metal percussion sound and chaos, when the engine is turned off, the percussion sound is almost unchanged, after the overhead valve spring is broken, the piston top colliding valve "dang" sound. There is a scrape after the side valve spring is broken, and the frequency of the knocking sound increases with the increase of the engine speed, but the volume change is not obvious.

3, piston knocking cylinder sound

Piston cylinder sound is usually the cause of piston and cylinder clearance is too large, in the engine work at the moment, the piston under the pressure of high pressure gas, swing in the cylinder and knock the cylinder wall, produce a sound, in addition, the piston against the oval, connecting rod bending or distortion, piston pin and connecting rod copper sleeve (bearing) rod big head bearing is too tight, will also cause the piston cylinder.

When the engine is idle, the knocking sound is clear, when the engine is cold, the knocking sound is obvious, after the temperature rises, the knocking sound is weakened or even disappeared, inject a small amount of engine lubricating oil (about 3mL) into the cylinder from the spark plug hole, and slowly step on the starting rod to drive the crankshaft to rotate for about 1 min. The lubricating oil flows between the piston and the cylinder, and the knocking sound is briefly weakened or disappeared when the engine is working.

Piston pin tapping sound causes:

The piston pin tapping sound is usually caused by: The piston pin and the connecting rod copper sleeve (connecting rod bearing itself) or the piston pin seat hole are not well matched, when the engine is working, the piston pin hits the connecting rod copper sleeve (bearing) or the piston pin seat hole, producing a knocking sound. When the engine is working at idle speed and medium speed, the "da-ta" knocking sound is clearer, the frequency of knocking sound increases with the increase of engine speed, and the engine temperature rises. The knocking sound does not weaken, sometimes it will be more obvious (this is the obvious difference with the piston knocking cylinder sound), when the fire is broken, the knocking sound will weaken or even disappear, and the moment of re-fire, there will be an obvious 1 sound (click) or 2 consecutive sounds (click) knocking sound;

The reason for the sound of piston ring leakage is usually: the piston ring and the cylinder wall are not sealed, the engine does work at the moment, the high pressure gas into the crankcase makes a sound, and the serious piston ring leakage sound is similar to the "cylinder sound". For four-stroke engines, the sound is reduced when the oil gauge (oil filler cap) is removed.

5, the knocking sound caused by deflagellation

When the engine suddenly accelerates or the motorcycle goes up the hill, a continuous sharp "tap" sound is emitted inside the cylinder, which is the knocking sound caused by dedetonation. The knocking sound caused by dedetonation is similar to the sound made by the excessive clearance between the piston pin and the small head bushing of the connecting rod. However, the knocking sound caused by deflagration will not occur at idle speed, and no sound can be heard by tapping the starting rod before starting. After starting, the sound of the piston pin is continuous and chaotic, and the knocking sound caused by deflagellation is most obvious when increasing the load and going uphill, and the sound is clearer.

The causes of deflagration are: overheating of the engine, excessive carbon accumulation in the combustion chamber, low spark plug heat value, the use of low octane gasoline, and early ignition time.

6, exhaust pipe cannon sound

Exhaust pipe discharge sound also occurs in two cases, one is due to poor engine work, so that the combustible mixture in the exhaust pipe combustion explosion and issued a "pop" sound, the sound is crisp, loud, while taking Mars or smoke, the other is due to the muffler itself broken, so that a part of the high-pressure exhaust gas directly into the atmosphere and issued a "pop" sound, its sound is weak, messy and uninterrupted.

In the former case, the causes of exhaust firing are: too much mixture, too late ignition time, gasoline deterioration or moisture, capacitor damage, four-stroke engine exhaust valve bite or no valve clearance.

Because the muffler is broken and produces the sound of blasting, it can generally only be re-welded, if the muffler tail opening is too large, it can also be used to clamp the opening with pliers.

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