I had a GS450L when I was a teenager. Lets just say that 450cc air cooled two valve twin with a 6 speed trans had no right to go like that. The bike was a cruiser with mini ape hanger type bars right from the factory too.
(can you say sleeper??)
That little 450 went like stink. I never lost a race to anything smaller than a 750.
I'll never forget the day I had the front end 2 feet off the ground while I spun the rear tire. ( I was a crazy rider then)
Or the fact that the factory redline on the bike was 10,500rpm, but, after the pods & rejetting it quit pulling at 12,000rpm!!
The pods were done to repair a torched airbox from a cold start backfire on a sub freezing day. The bike would barely run without the airbox. It was very restrictive.
It saw 12,000rpm every day a couple times & never complained about it either. That engine just whined on the top end of the rev range.
Unfortunately, in a fit of stupidity I traded it off.