What Causes the Puttering Sound in a Gasoline Generator?
2 Answers
The causes of a puttering sound in a gasoline generator are as follows: 1. Engine misfire: An engine misfire mainly refers to one or more cylinders not functioning properly, manifested as: intermittent exhaust gas flow with noticeable pauses, severe shaking of the exhaust pipe, and a clear 'puttering' or thumping sound from the engine. This phenomenon is often closely related to ignition coil failure. 2. Overly rich air-fuel mixture: When the engine's air-fuel mixture is too rich, the symptoms include: difficulty starting the engine; hard acceleration after starting, uneven engine operation; black smoke from the exhaust pipe accompanied by a puttering sound, sometimes backfiring; reduced engine power and increased fuel consumption. This is mostly related to carbon buildup, clogged filters, etc. 3. Cold start: During a cold start, the engine's lubrication is less effective, the oil has poor fluidity and is more viscous, leading to mechanical wear noises. Additionally, during a cold start, the coolant temperature is low, the air-fuel mixture is richer, and incomplete combustion can cause the engine to shake and produce a puttering sound. This is generally considered normal.
I've repaired many sputtering generators, and the noise is most likely due to fuel system or ignition issues. First, check if the spark plugs are fouled with carbon deposits causing weak sparks—remove them, clean the electrodes, and adjust the gap to 0.7mm. A dirty carburetor is the worst culprit; last time, my neighbor's machine was sputtering with black smoke, and upon disassembling the carburetor, we found the fuel nozzle half-clogged with varnish. Aging or cracked rubber fuel lines can leak air—pinch the hose at idle; if the sound stabilizes, there's a vacuum leak. A less common issue is a rusted-through muffler, where insufficient exhaust backpressure causes abnormal combustion. Block the exhaust pipe outlet with your finger (careful, it's hot!)—if the sputtering stops, the muffler needs replacement. Finally, remember to check the fuel filter; too much debris restricts fuel flow, making the engine run rough.