Hi guys - looking for your expertise again.
Just did a oil change, filter change and coolant changed (did it many times before) and just changed my spark plugs (stock plugs). After reassembling everything (no extra screws of bits left over) - when I start my bike (2008 Ninja zx 6r) - I hear a high pitch, constant buzzing noise from under the gas tank.
This noise is only when the engine is running, is constant and is audible (over the sound of the engine) when I bring my ear close to the thank. I never had this sound before. I doubt this is related to the oil or coolant change, so it must be something related to the spark plug change.
It doesn't have a rattling sound (so not likely a loose part) and sounds similar to the sound when you first turn on all the electricals on the bike just before you start it.
Any ideas? (spark plug change went smoothly, all connectors re-assembled, doesn't sound like mis-firing-?). It sounds electrical versus a mechanical sound.