One night long ago after a clandestine street race, a Cycle World staffer, who shall remain nameless, returned home, only to hear a strange squeaking noise emanating from his motorcycle engine. A subsequent teardown revealed rubbery blue chunks of silicone sealer inside the cylinder head’s oil galleys. Oh, they were pretty—rivaling a geode found in the desert—but they also did a terrific job of blocking oil flow to the camshaft lobes and rocker arms. Hence, the squeaks as dry lobes pushed against dry rockers. And that was the night during which the importance of choosing the correct sealers for the job became permanently implanted in his brain, and ours. Not every gasket surface requires sealer, of course. But if you need some, here are three good ones for motorcycle jobs.