So whats if it's not the plugs. Anyone got any suggestions? Its a 2000 Honda interceptor with 20,000. I have changed the oil and air filter very recently. The chain is lubed. I have never over-revved it. At about 5000rpm, I notice a loss of power, when I used to notice a gain. From there up, whenever I let off the throttle, it feels like I am applying the brakes, but obviously am not. It doesn't sound any different, and the power change is noticable to me, but not to others (Wrillo). Any thoughts?