Do crank seals sometimes start leaking slowly? Or do they just go all at once and start putting out clouds of smoke? Reason I'm wondering, KDX fouled a plug again today. It's also started spooging like crazy in the last 3-4 rides. But it's not smoking any more than normal that I can tell. It's jetted 40/150 with a CEL needle in the second notch. I've been in the carb a few times lately dealing with the clogged pilot jet problem that was solved with an inline fuel filter. Checked the float level, but didn't change it. Only carb changes I've made lately was putting the airbox lid back on (minus the snorkel), going from a 152 main to a 150, and adding the CEL needle. But all this (except the airbox lid) was after it fouled the first plug (which I thought might be a fluke, but apparently not). So, on the surface, nothing in the carb area sounds to be at fault. That leaves me wondering about a very slightly leaking crank seal adding a small amount of extra oil, enough to cause some pretty serious spooging and fouled plugs every 50-60 miles or so. Bike starts and runs great otherwise. Thoughts on this, and any other ideas..