The owner's manual says 87 unleaded will do, but I do run 91 premium in the bike. I had a 91 and 94 DR350 and each emitted a somewhat similar noise, the oil pump gear on those bikes drives off the crankshaft, and during power stroke the gear will rattle some. Removing the side case and putting a slim shim on the shaft took the wobble and rattle away on both those bikes. Just wondering if the new Z has the same set up. I'm just an old guy who remembers when bikes were jetted with the biggest carbs and jets one could fit on the ole air pump of an engine, so these newer CARB bikes with water cooling are new to me.
Oh for the days of when I could actually hang on to and keep the rubber side up on my Husky 500XC firecraker of a bike. Almost hovering over the sands of what was once the East Mojave desert.
Any ideas are appreciated.