happened to me after washing the bike, started the bike in neutral while it was on the rear stand. rear wheel starts turning, albeit slowly. i say wtf!? and i wasn't touching anything! sounded louder than normal and saw the idle revs were around 5k. turned it off with the key and started again. same thing. used the kill switch then tried again and it was back to normal. i've got no explanation for it. i wish i took a video coz i can't believe it happened either.

 

Happens to me every now and then. Just give it a bit of throttle, and it should get it's act together.

 

Sounds like a sticky throttle cable to me.

 

I agree. ^

or if you have adjusted your throttle cable lately you may gone too far. You gotta turn the bars from lock to lock to make sure the cable doesn't pull or bind.

 

Throttle should be off during startup, so it would stick in the off position if it was sticky, no?

 

My bike and a friends bike does that too.
No sticky throttles on either bike.
There is something else causing it.
Both are bikes behave like someone is twisting the throttle a few times then it settles down after just seconds!

 

with your bikes turned on and idling at normal rpm and the bars facing forward.. turn the bars from lock to lock...see if your rpms fluctuate any. If they do, your throttle cable needs adjusting. If not, the be sure to lube your cable.

 

on a really rainy or chill
cold day,when i start my bike,rpms are
around 2000-2500rpm,mostly fluctuating
but settles down to steady solid 1500rpm when the c-h meter starts showing 1bar
consulted with my friends who
own same bikes,they too agreed around 2000rpm fluctuation is there,for initial 10seconds average

but as you are saying,the 5000-6000 rpm seem a lot high than what we are having.

Check the cable for tightening when turning handlebars
as others told or get the bike checked up at svc...

 

this is the thread u were looking for....

http://www.cbr250.net/forum/cbr250-problems-issues/4720-start-up-normal.html

used to happen with my cbr too...and still happens at times....yet dont know why...
bdw im here in ACT and temp goes down to as less as -5 degrees at times.. may b thats the reason i recon...

 

Thanks guys, I'll keep an eye on it.
It happened again on Sunday morning (both at around 730 in the morning) but I switched it off and on again and it was OK.

If it keeps happening I'll take it back to the dealer.

Chinmay, it wasnt particularly cold here in WA, maybe 11 degrees or so. My bike is stored outside (but under cover) though.

Also, thanks for the link to the thread.

 

Mine has done it on and off since I got it just something in the computer I've alway just given throttle little twist and it comes down.


Sent from my Motorcycle iPhone app

 

It happens when engine gets cold and at morning startup. It's normal case. When the engine start at cold it understands that it need the sufficient heat on engine to not create any bad revving. It also happens when the battery goes very low it automatically rises the rpm to get minimum charged the battery. Some many reasons are there for automatically revving on high rpm when starts at morning with help of many sensors.
I suggest when you start engine at first time everyday keep it on idle do not turn off the engine until it gets the minimum rpm on idle.