What is the reason for abnormal engine noise when the motorcycle is not tilted?
3 Answers
Motorcycle abnormal engine noise when not tilted is caused by abnormal piston operation. Normal engine sounds: If the engine is in good technical condition, during idle operation, only a uniform droning sound can be heard. At medium speed operation, the sound is uniform and crisp. During acceleration operation, it emits a powerful and smooth droning sound. These are all normal sounds. Abnormal engine sounds: If during engine operation, sounds similar to piston and cylinder wall collisions are heard, knocking sounds from burned-out bearings, or bubbling sounds from excessive fuel intake in the carburetor, etc., these all belong to abnormal sounds.
The other day when I was riding my motorcycle, I noticed a clunking sound from the engine when upright, which was quite alarming. It might be due to a loose or worn-out chain, especially when riding straight without leaning, as the tension varies more. Another possibility is severe wear in the rear wheel bearings, which tends to be more noticeable on flat roads. Once, after I adjusted the chain tension myself, the noise disappeared. You could start by checking the chain and see if the oil needs changing—dirty or insufficient oil can cause internal engine friction noises. Additionally, loose engine mounting bolts can produce similar sounds, so try tightening them. If the problem persists, it’s best to consult a professional to avoid any dangers on the road—safety comes first. Remember, regular motorcycle maintenance is key; frequent checks on the chain and bearings can extend their lifespan.
As a frequent rider, I think this situation is quite common, mostly due to loose or aging mechanical components. Start by checking the chain—if it's loose, it tends to make a clicking noise when riding straight. Next, inspect the rear wheel bearings, as wear can make the sound sharper. Loose engine bolts are often the root cause. Low oil levels may also worsen the noise, so check the dipstick and top up if needed. I recommend carrying a tool kit when riding—if you hear unusual noises, stop and do a quick tightening. Don’t wait until it gets worse to fix it. If the sound bothers you while riding, pull over immediately to inspect, as this can prevent major breakdowns. Regular maintenance saves money and keeps you worry-free.
