Just wondering if you already verified engine timing at the crank and timing belt pulley's?
Not yet but that is on the list. I don't recall timing belt replacement intervals and my bikes has 39,000 miles on it. Even so, there's no telling if any mods or upgrades were done to the bike unless I remove the lower front cover and check the timing. It's possible the guy before me might have installed a 4 degree timing wheel, and that might explain the spark knocking during the summer when using 87 Octane. More to come on this.