Highway RPM

There's nothing like the hum of a well tuned 4 cylinder bike just running along at 5 or 6000 rpm
No put put putting

Makin ponies. :laugh:
Steve

swest wrote: Next time you need a chain, change the gearing. I'm at 3500 at 55.
Steve

Yea, but....

You're on a KZ1000, he's on a KZ650. That KZ1000 has more low end grunt . Unlike the KZ1000, the KZ650 makes a little less than 25 hp at 3500 rpm, so cruising along at highway speeds with that little amount of power might be stretching the envelope a bit. At 4500 rpm the KZ650 makes 30 hp which is sufficient to maintain 60 mph without straining. KZ650 power comes on pretty strong once you cross 6000 rpm and peaks at 64 hp at 8500 rpm. Ed

Good point. There has to be a happy medium in there somewhere.
Steve

People keep forgetting that this motorcycles were made when top speed limits was 55mph.
Both of my cycles have Kerker headers with 2" race baffles and the bike is screaming at 80....around 4800rpm.
Friend of mine has one with stock exhaust and thing just cruises along....does not feel like the engine is to high on RPMs.

I happen to look for a 6 ' Speedo .
But it is my fault , after an hour with this under the ear !

Yes....I use ear plugs when riding.

That's cheatin. :whistle:
Steve

Hah.. ok so it comes down to the bike is geared for the speed limit of 55. I figured that as I've read that elsewhere with other bikes of the era. I don't want to do any engine mods so I'll just keep enjoying her around town and look a big brother to add to the collection for traveling
The modern Kawasaki Versys or Honda 500/700x are pretty darn cool.

I suspect the KZ650 gearing was actually designed to provide roughly the highest top speed that the engine’s horsepower can deliver. In the 1970’s (just like today) the big focus of motorcycle companies was quickness and speed competition between the various bikes. The KZ650 has 64 hp, and regardless of the sprocket sizes and tranny gearing 120 mph is about the fastest that much hp can push the bike and rider through the air resistance at that speed. The engine redlines at 9000 rpm and at that engine speed in 5th gear the bike will travel 120 mph. By design or coincidence, the gearing that enables the bike to reach its top speed just as the engine speed reaches redline also enables the bike to run the ¼ mile in the shortest amount of time. So that gearing enabled Kawasaki to compete with other bikes with the same or even more engine displacement. With that 9000rpm /120mph gearing the engine turns 4500rpm at 60mph. Considering that 4500rpm is a mere 50% of the engine’s maximum rpm it is not stressing the engine at that rpm. Ed