Extra High RPM on Ninja 250

victorbrca

victorbrca

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On the way back from work today I noticed that my Ninja 250 had the RPM all they way up, a lot more than usual. At 120km/h the RPM was at around 11, and at 130km/h it was at 12 (speed as per GPS), both in the last gear.

I know today it was really hot... would the heat have any impact on this? Anything I should watch for?
 
If the engine sound and response were normal, most likely the tachometer is acting up (not displaying the correct reading).
 
victorbrca said:
On the way back from work today I noticed that my Ninja 250 had the RPM all they way up, a lot more than usual. At 120km/h the RPM was at around 11, and at 130km/h it was at 12 (speed as per GPS), both in the last gear.

I know today it was really hot... would the heat have any impact on this? Anything I should watch for?
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Mine does about the same. I've seen people hit 160/170 km/hr on a 250 ninja, but they were redlining. 120 or 130 at 11 rpm doesn't sound that strange for that bike. If there's something wrong and u figure it out, let me know.
 
would wind play a part?

i know my friend on her 250 was following me westbound last night, crazy head wind. she couldnt surpass 120 at full throttle.

wouldnt that wind the rpm's up?
 
My cbr125 hits 11k rpm @ about 125km/h!

I think there was actually a thread in the technical section stating that the weather was the "issue".
 
LoneRonin said:
it should be fine, but make sure your choke isn't on...some people forget, also check your idle screw, when its fully warm it should idle at 1.3-1.5 rpm, make sure its not higher
and yes high heat and humidity make a difference especially on our little carbed bikes, refer to this thread...

http://www.gtamotorcycle.com/vbforum/showthread.php?157786-Lower-top-speed-in-hot-weather
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Actually I rode to work with the choke 1/3 open. I completely forgot that I still had a bit on. But the issue was on the way back.

My idle speed is ok. I set it to the exact place where I want it. But thanks for the link... it makes sense.
 
The new gen 250's seem to have a cdi that is susceptible to heat, when it gets too hot the tach displays a higher rpm than the engine is actually turning). If your rpm is lower in cooler weather for the same speed, I would suspect this.
 
NealT said:
The new gen 250's seem to have a cdi that is susceptible to heat, when it gets too hot the tach displays a higher rpm than the engine is actually turning). If your rpm is lower in cooler weather for the same speed, I would suspect this.
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RPM was back to normal this weekend... so looks like this was indeed the cause.
 
:lol: jeeezus at this thread :lol:

djbordie said:
would wind play a part?

i know my friend on her 250 was following me westbound last night, crazy head wind. she couldnt surpass 120 at full throttle.

wouldnt that wind the rpm's up?
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Revolutions of the crank are directly tied to the rear wheel through the transmission. The engine always spins X amount of times for XXX speed in X gear... this isn't "variable", it's a physical link :lol:
 
mmmnaked said:
:lol: jeeezus at this thread :lol:




Revolutions of the crank are directly tied to the rear wheel through the transmission. The engine always spins X amount of times for XXX speed in X gear... this isn't "variable", it's a physical link :lol:
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I was thinking the same thing. Only AUTOMATIC transmissions can have the RPM increase or decrease at the same speed in the same gear. Manuals have a direct link from the engine to the wheels and the engine will always turn at the same speed every time at the same velocity in the same gear. The only way this could happen is if your clutch is slipping and you would probably fry the clutch fairly quickly. Even automatics with unusual RPM variations when cruising are probably suffering from slipping clutches or coverter lockup slippage. Other than that the only possible explanation is some kind of RPM sensor/tach issue.
 
While we're on this topic..is it okay for a ninja to be redlined for so long? 90% of my riding is highway and I'm usually cruising at 140-150..which puts me about 1000 rpm from redline. Are these little quarter liters fine with living at high revs?
 
overkill13 said:
I was thinking the same thing. Only AUTOMATIC transmissions can have the RPM increase or decrease at the same speed in the same gear. Manuals have a direct link from the engine to the wheels and the engine will always turn at the same speed every time at the same velocity in the same gear. The only way this could happen is if your clutch is slipping and you would probably fry the clutch fairly quickly. Even automatics with unusual RPM variations when cruising are probably suffering from slipping clutches or coverter lockup slippage. Other than that the only possible explanation is some kind of RPM sensor/tach issue.
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Wet clutch, wouldn't really have a problem, but thats beside the point, probably a sensor or gauge issue.
DOHC1 said:
While we're on this topic..is it okay for a ninja to be redlined for so long? 90% of my riding is highway and I'm usually cruising at 140-150..which puts me about 1000 rpm from redline. Are these little quarter liters fine with living at high revs?
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just fyi bad idea to put traffic infractions on a public forum. I personaly wouldn't ride it that hard all the time, 130 is a good speed where you're in the power band but still have some room to play for passing. Also change to a synthetic oil and swap it every 3000k instead of 5. The high temp will need a better lube to resist thermal breakdown and need to be change more frequent.
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