What is the bhp for a Honda cb450 nighthawk?

Answer 1

I bought an '82 450 Nighthawk new and my son now rides it. If memory serves, I believe it was quoted as having 36 horsepower. I also own a 2004 1300 VTX cruiser which is rated at 72 hp on the motor with about 60 hp at the rear wheel. The shaft drive causes greater losses than the chain drive of the Nighthawk. With myself and wife onboard the VTX (our combined weight is 302 pounds) and my son (142 pounds) on the Nighthawk, we are very close to dead even in acceleration. Of course I'm spottin' him about 400 pounds in total weight. The other difference is that the 1300 V-Twin motor of the VTX makes big torque at lower rpm whereas the power curve of the Nighthawk comes in above 6500 rpm. The Nighthawk also has an extra cog in the gearbox. You can do wonders with revs and gears but I like the low down grunt of the big V-Twin and of course, there's no comparison in sound although the Nighthawk has a relatively pleasant note. One modification I made to the Nighthawk, which TOTALLY transformed the bike, was a replacement of the Front Sprocket with one which had two less teeth. This was the biggest change I could make and have the chain surive according to the dealer. Effectively, it took the revs in 6th gear at 60 mph from 4,400 to 5,000. Although there was a slight increase in engine noise, this still left the revs 1,000 lower than what they'd been with Honda's previous 400's with the 5 speed transmission. That 6th gear was a VERY tall overdrive. Swapping the front sprocket yielded better acceleration, better fuel economy since it wasn't lugging against a headwind, and a much higher top speed. Prior to the switch, the engine could redline (9,200 rpm in 5th gear) but would then slow down after the shift to 6th gear as it fell off the power curve. After the switch, the engine will now pull 8,800 rpm in 6th gear (just shy of redline), which is just about perfect gearing. Top speed rose from an indicated 100 mph to almost 107 mph. Of course we all know motorcycle speedometers are notoriously inaccurate. True top speed is probably in the mid 90 mph range which was fast enough for me. Although I enjoy my VTX immensely, it is still a blast to hop on the Nighthawk for a spin. It was/is a really nice bike and the ergonomics made it a supreme long distance riding pleasure. Still love it's seat comfort.