First off I know smooth and quiet is not in an FJ's vocabulary. I have the starter chain jingle typical 2000ish rpm vibration but what is the diesel truck hiding behind the clutch cover? In neutral or clutch lever pulled, combined both together seems to quieten a little. Is this a major concern or typical FJ quirks.
Wow stumped everyone. Ended up being ethanol...I never use it in my bike being by the biggest lake in S.C. 93 octane non ethanol is easy to come by cept other day put in 89 e10 to get home. Best I can figure timing on bike is set to burn higher octane resulting in eratic crank rotation which would cause slop in drive gear to transmission to chuggle (best term I can come up with) hence the noise. Added lucas octane boost and 93 now she is back to normal actually with boost even smoother. Well this is my theory.
Well ya, sometimes its just a bad tank of gas.
My stepson filled off the same pump had no issues with his bike thats designed to accept such fuel.