1,200 - 1,400 - Idle

Idle rev's, according to the manual, should be set between 1,200 RPM and 1,400 RPM.

2,500 - Neutral Limmit

Again according to the manual... when the motorcycle is in Natural Gear the rev's should never exceed 2,500 RPM. 'Do not race the engine above 2,500RPM' so the manual says.

I can only presume they are refiring to when you first start the bike with the choke on or if you're just sitting there revving the engine?

Email me if you know what it's about

5,000 - Downshift Threshold

5 grand downshift threshold. 

According to the manual if you're slowing down (under 'normal' circumstances) and shifting down gears, do not downshift above 5,000 RPM. This will over time damage the gearbox.

If you must downshift above 5,000 RPM (on the track, in the mountains or in a hurry), you must manually synchro when you shift down.

6,000 - Min. Cru.

6 Grand. This is what I would call the minimum cruise rev. 

Prolonged use below 5,000 RPM will add to cam chain ware. Hence I use 6,000 RPM as a minimum on city and sub-urban roads.  

8,000 - Fun Factor.

Below 8,000 RPM the ZZR250 is really lazy lacking torque. However once the 8,000 RPM mark is reached,  the motorcycle becomes much more fun as the mid-range starts to take effect.

Now, I've ridden a ZX250R which is well known for it's top end power and a red line at 19,000 RPM. If I had to compare the two in performance I would say the ninja has more top-end, but the ZZR has more mid-range. Believe it or not.

10,000 - Torque.

At 10,000 RPM the little 248cc puts out it's maximum torque.

24.5 N-m @ 10,000RPM

12,000 - Horsepower.

At 12,000 RPM the engine puts out it's maximum horsepower.

27.9 kW @ 12,000 RPM

Resonant Frequencies

In addition to revs and performance the engine also has it's note. The ZZR engine resonates it's tone at approx every 3,000 RPM.