The last thing you want to hear as you're riding along is a strange sound emanating from your motorcycle. Any new noises, regardless of how quiet or intermittent they are, could indicate something's wrong. As problems only tend to get worse the longer they're left, don't be tempted to ignore the noise in the hope it'll go away on its own. Sometimes, the noise could indicate a trivial issue that's simple and quick to resolve. Other times, it could indicate a major issue and a major repair bill down the line. Although vintage and older motorcycles are the most prone to problems, even brand new models can sometimes get worryingly chatty. If you're concerned about the noises your motorcycle is making, bring yourself up to speed with these five common motorcycle sounds and what they mean.
1. Snap, Crackle, Pop
If you hear a snap, crackle, and pop, don't assume it's your breakfast cereal making a re-appearance. As Ultimate Motorcycling notes, it's much more likely to indicate a leak. If the noise is accompanied by a hesitating engine, it could also be the result of ignition energy from a crack in the spark plug cap or spark plug wire insulation shorting against the frame, engine, or another engine component. Unfortunately, this is one of those sounds you can't choose to ignore in the hope it'll go away. Although you might ultimately need to book an inspection with a dealership, you can start by completing a preliminary inspection of the caps and wires yourself. Some people suggest running the engine in dim conditions so you can check for any arching from the spark plug components. However, as this can have serious consequences if there's any fuel vapor lingering, play it safe and avoid the advice. Fortunately, both spark plug caps and spark plug wire insulation are cheap enough to replace without blowing a hole in your budget.
According to MCN, a gurgling sound is more than likely to be rooted in a problem with your cooling system. Coolant should circulate without making any noise at all: any hint of gurgling could indicate something's amiss. To get to the bottom of any suspicious noises, start by checking the coolant level: if there's a drop, you've got a problem. When air pockets form, the pump loses its ability to circulate the coolant properly, leading to frothing and boiling when it gets trapped in hot spots. Top the coolant back up. If it drops again, you could be looking at a leaking seal or gasket. If the coolant is bubbling or being pushed into the header tank, you might have a blown head gasket or another overheating issue. Unfortunately, neither one of them spells good things for your repair bill.
According to motor.onehowto.com, a solid-sounding knocking coming from deep in the motor spells big trouble. Usually, it's related to the crankshaft and conrods on the engine's bottom end. If the big-end shells wear away or the bearings collapse as you're riding, they can make the engine seize and cause a crash. If you hear a knocking or metallic clucking sound coming from the motor, don't continue riding. Bring the motorcycle to a safe stop as soon as possible. Trying to clear the engine by revving up won't help and may even exacerbate the problem further. Unfortunately, this kind of fault isn't one you'll be able to resolve on your own unless you're experienced at motorcycle maintenance. Even more unfortunately, the cost of repair is likely to be significant.
A grinding sound is never welcome, regardless of how soft or quiet it is at first. Even if the grinding noise is vague, immediate action is required to avoid turning what could already be a significant problem into an even bigger one. If the noise is intermittent, it could be that the front or rear brake pads need replacing. If worn pads are to blame, you might notice the handlebars vibrate when you brake. Even if the brake pads aren't showing any obvious signs of wear, they might still be causing the noise. Certain types of brake pads get exceptionally vocal under the influence of moisture or high humidity. In these cases, the problem will usually clear up after the brakes are used a few times.
Sometimes, a grinding noise can come about if a caliper sticks and makes a brake pad drag. To check if this is the problem, try pushing the bike along for a few yards by hand. You could also try riding for a short distance before checking the heat of the rotor. If the motorcycle seems to drag rather than move along smoothly, or if the rotor feels hot, you could well be dealing with a sticking caliper. If the grinding noise seems to be emanating from the engine or the transmission, it could indicate a bearing failing. As this needs prompt investigation, bring the bike to a stop straight away. If the wheel bearings are at fault, continuing to ride could result in wheel lock. Occasionally, a grinding sound could indicate something as simple as the spline of the rear-drive gear needing greasing. Simple though the problem is and simple though it is to rectify, do it sooner rather than later: leave it for too long, and you might inadvertently cause excess wear.
If your motorcycle is booing and hissing, it's unlikely to be a comment on your riding style. It's far more likely to be the sound of your tire deflating. Unwelcome though the sound may be, at least it means you can take the necessary action now, rather than carrying on blithely unaware and risking a crash as a result. Another potential cause of a hissing sound is a flooded cell battery that's connected to a charging system that is overcharging the battery to the point that gas is being released into the overflow tube or out of the cell cap or a crack in the case. Left untreated, the battery could burst. To avoid a potentially dangerous situation, kill the engine and bring the bike to a safe stop immediately so you can troubleshoot. A blown gasket, a radiator leak, or an exhaust system leak could all potentially be to blame for the troubling hissing. Although none of these are going to land you in hot water immediately, all will require attention as soon as you're able to get the bike into a dealership.
Written by Benjamin Smith
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