Was riding my 2000 Tomos Targa yesterday and I suddenly lost power. Thought I may have heard a little click, like the sound of something breaking, right before I lost power. After it happened, the engine still ran fine and I could even get the clutch to engage at about 8 mph, but there was absolutely no power. Any ideas? Broken piston ring? Fouled exhaust? (but I've had that problem and it never led to total loss of power like this time). Thanks.