WHY SHOOTS FROM THE SILENCER OF A MOTORCYCLE?
On domestic motorcycles, a problem often arises related to the appearance of loud noises in the muffler. Even drivers of foreign vehicles often suffer from “machine gun bursts” that accompany a sharp increase or decrease in speed. Getting rid of this trouble can be quite difficult. However, if you understand why the motorcycle shoots at the muffler, you can eliminate loud noises that disturb public peace.
Nature of the problem
Most often, loud pops in the muffler of two-wheeled vehicles are heard when a lean mixture is fed into the motor. The reason for its formation may be the use of low-quality gasoline, saturated with water and non-combustible impurities, or improper adjustment of the intake system. The air-fuel mixture burns out only partially – its remains are splashed out into a hot muffler, where it explodes with sharp unpleasant sounds. The symptom of a lean mixture is popping “bursts” that increase with increasing speed.
In powerful motorcycles, the completely opposite problem is more often encountered, associated with the supply of an over-enriched mixture. There is not enough oxygen for its combustion, which leads to the subsidence of gas condensate on the walls of the muffler. When the “critical mass” is reached, ignition of the fuel occurs outside the engine, as a result of which one loud pop is heard. If the problem is not resolved, within 1-2 months the contents of the muffler will simply burn out and it will turn into a “forward flow”.
Incomplete combustion of the mixture may be caused by a malfunction in the ignition system. In the absence of a spark, the cylinder’s working cycle is skipped and gasoline enters the muffler in full. Loud are most often heard in this case at high speeds. The problem is also fraught with complete burnout of the muffler from the inside. Misfire is often accompanied by beautiful visual effects – when the gas is blown out of the exhaust pipes, jets of flame fly out.
Another option is the depletion of the mixture in the intake system caused by the ingress of air, dirt or water into it. Naturally, the fuel does not burn completely and drops of gasoline form on the walls of the muffler, which burn with a sharp characteristic sound. In any case, the malfunction of the motorcycle must be fixed as soon as possible so as not to encounter more serious repairs.
Reason and solution
The easiest way to get rid of pops on a carburetor motorcycle is to simply move the needle valve to another position, changing the degree of saturation of the mixture with gasoline. It is better to entrust this operation to a specialist, since far from everyone can finely adjust the carburetor. In the presence of electronic fuel injection, it is impossible to change the gasoline supply parameters independently – the control unit will have to be flashed at a specialized service station.
Carburetor in motorcycle
It happens that a motorcycle shoots at a muffler and a carburetor – this is often found on domestic “Urals” and imported choppers with a large cylinder volume. The problem is the clogging of the air intake mixture. To eliminate it, it is worth changing the filters and sealing gaskets, as well as checking how tight the pipes are to the receiving fittings, and whether there are large cracks in them.
Very often, pops appear after replacing the muffler with an abnormal one or cutting out openings in it to eliminate resistance to exhaust gases. Especially strongly unpleasant sounds are manifested when installing the “forward flow”. The reason is to create a strong vacuum, which leads to the depletion of the air-fuel mixture. In powerful imported motorcycles, a system of afterburning exhaust gases is often used, which reduces their toxicity – after removing the standard muffler, its work becomes clearly audible. To eliminate shots after changing the silencer, you must:
Reconfigure carburetor or reflash control unit;
Install filters with a different bandwidth;
Disconnect exhaust afterburning system.
In sports motorcycles whose engines operate at high speeds, the problem with shots can be associated with a speed limiter or crankshaft speed. When a certain indicator is reached, the fuel supply may remain unchanged for a while, while the number of flashes is reduced. Accordingly, a huge amount of gasoline enters the muffler, which explodes with a jerky sound, forming a “machine gun burst”. It is especially well heard when the gas is released after active acceleration. It is impossible to eliminate such a problem without reducing the engine resource – you have to change your driving style so as not to annoy yourself and those around you with unpleasant loud pops.
Sport bike speedometer
It is worth paying attention to the ignition system – misfires of flashes can be associated with its malfunction. Carefully inspect the high-voltage wires – they should not have cracks or delamination of the insulation. Having unscrewed the candles, check if there is a specific coating on their surface.