My bike emits a loud knocking noise when starting off up a slight hill, even using only 1/4 throttle (as still running in). Sounds like piston slap although a friend thought it might be pre-ignition that can be damaging. I changed to a higher octane petrol that can reduce pre-ignition but made no difference. It only occurs at slow speeds and if I ease right off it stops, but I don't like the sound. I didn't have it on my 500 Bullet that I bought new so am surprised at having it on the GT.
Has anybody else experienced that knocking?