kz 650 rpm limit ?

Just wondering what is the max rpm you want to cruse with this bike would keeping it at 6000 rpm for say a 2 hr ride be bad for the engine ?

I can't say it would do much harm to the engine, but depending on where you live you may rack up some tickets. On the KZ650 with stock gearing 6000 rpm = 80 mph. Ed

Rev limit is usually set by valve bounce, where the springs can't shut the valves quick enough -this usually happens well past the redline. Most untuned motors start running out of steam at the redline anyway,

6000 rpm is the average cruising speed of most zeds. All the big 4 cyl zeds are well designed and 30 years later and a dozen or more previous ownersTthey are mostly still ok.

During development Honda had a fireblade engine on a dyno on the redline for 7 days, afterwards it was stipped and found all to be within tolerances.

Don't thrash them when cold and use decent oil . The whole engine 'floats' on oil, apart from cold starts.

most 650 owners would say 4000 is the "natural" cruising speed of that engine. 6 grand isn't going to hurt it, hell they turn 10,000 or more in stock configuration.

Point's bounce will shut it off before it rev.'s enough to hurt it.

i find that im at about 5 grand going around 110km and im at grand im going around 120 - 125km does this sound right ? or maybe i dont have the stock sprockets ? or maybe speedo is off ?

The speedo is off a little which is normal on these bikes. At 5000 rpm you're probably moving at about 66-67mph (106-108kph). Ed

You never want to keep an engine at a steady RPM for a long time. You should vary your RPM for proper engine wear across the RPM range.

If your doing highway riding, you will be in and out of traffic and rpm's will moderate just fine.

Maybe not for running -in UK loads of despatch riders bikes have done starship miles mainly done at motorway speed, many done 100k miles plus out of old kawasaki GT550's ,GT750's etc.

Most mega high miler cars and commercial vehicles, some over 1,000,000 miles have clocked 90 percent of their miles on motorways, many in speed limited mode. Not aware of how steady rpm is detrimental to an engine?