My Suzuki DL1000 V-Strom has developed a knocking noise that seems to be coming from somewhere down in the engine cases. I only hear the noise at idle, and it goes away as soon as I open the throttle. Otherwise, the engine runs perfectly. The V-Strom only has 14,000km on it, and of the half-dozen bikes I have owned so far, I like this one the best, so I hope this knocking isn't a sign of an impending major failure.

The local mechanic says I should not worry to much, but most of the motorcycles he works on are not bigger than 150cc. So, what should I do?

Over the past few years, I've ridden quite a few Suzuki's powered by various iterations of the same basic 1000cc V-Twin engine that's in your V-Strom, and several of them have made knocking sounds like the one you describe. Those noises are not generated by failing components in the engine's bottom end but instead are the result of either one specific factor or a combination of several: a too-low or uneven idle; crankshaft side play that is at the large end of the allowable tolerance; fiber clutch plates whose tabs have become a loose fit in the outer clutch hub; and relaxed spring pressure in the auxiliary primary drive gear.

Usually, such sounds are barely perceptible on most Suzuki V-Twins, but accumulated wear and / or normal manufacturing tolerances can cause some of those engines to be noisier than others...