View Full Version : help D= cbr250

6th April 2006, 10:04
today started out like the rest, start up the bike, let it warm up for about 5 mins then off I go.
All was normal till about 10 mins into my trip into polytec..
I'd twist the throttle and nothing would really happen..
seemed pretty strange to me, so i tried again, all was normal.. hmm??
got to the first lot of traffic lights, bike is idling at about 1500.. normal..
twist throttle to take off and the bike bogs, i get nothing.. release and twist a few more times and off she goes.. this happens all the way to the next lot of lights, somethings not right..
Now it's idling at 5000rpm.. tried blipping throttle and it goes down to about 2k then climbs back up to 5k again
It's like this all the way through town till i get to polytec and turn it off, had a test to sit you see..
random approach to throttle working and idling very high.
This only started happening today.

I'm really not sure what the hell is going on, but it's not fun..
Something's buggered with my bike and i don't know what..
And ideas?? I might leave it at the shop today and see if they can fix it..

6th April 2006, 11:35
Sounds like a fuel thing. Try draining the carbs and putting fresh fuel in

6th April 2006, 11:39
a fuel thing you say, wouldn't have anything to do with why they want to replace my fuel tap "whenever you can spare the bike" hmmm?

Thanks Sniper =) I'll have a look

6th April 2006, 11:41
Could possibly be, but I don't see how a faulty fuel tap can cause a rise to 5000rpm. Also, have you check your throttle cable is correctly adjusted and oiled? How old is the fuel in the bike?

6th April 2006, 11:46
I don't know much about bikes ">>
I'll try find a manual eventually..
Maybe the choke is stuck.. or something..

I can't really check most of this stuff at the moment, i'm at polytec. hehe

6th April 2006, 13:05
Just went for a ride to port chalmers and back, noticed some things..

#1 Bike is starting a lot "easier" than usual from cold. didn't need to use choke, or hold the rev's up manually. It sat at 2k happily.. for 2 mins, then went dead.
Restarted, bike was "normal" sitting at 500-1000 rpm, have to keep blipping it to keep revs up.

#2 The nut holding throttle cable on was loose, completely undone and spinning about on the cable, so i screwed it back on. No improvement noticed.'

so, i'm still stumped. It's still randomly idling @ 5000, or nothing (after it's been going for a while).
Take offs are horrible events as it threatens to die, crawls over intersections, then rockets off. In fact the only time it seems to work properly is at 10k+ rpm (great fun =D)
I want it back to working like it used to.. =(

I'll take it into the shop later on and see if they can do anything about it. (They better, i've only had it about 2 weeks..)

Any more advice from anyone will be greatly appreciated

6th April 2006, 13:14
Sounds like a mixture problem then. Might be rich.

PM me your home address and I'll burn off a copy of the CBR manual and post it to you.

6th April 2006, 13:32
From what I know about engines it sounds extremly rich???

Check the air intake, air filter and all the pipe (hose, ducting, etc) to get the air into the engine, something could be blocking the air getting into the engine. Does it change at all when you use the choke?

crash harry
6th April 2006, 14:30
Sounds like a choke problem to me.

I would say that if you take the tank off and have a look, you'll find it will be fairly obvious. Have a look around the choke cable, see if it is still attached and if the return spring for the choke is still in one piece.

If you aren't confident to go poking around in there, you may be best to take it to a mechanic or find someone local who knows what they're looking at.
(I'd offer to come have a look, but you're at the other end of the country...)

6th April 2006, 16:03
I'm confused :P
Went to go home, start up the bike and yay! it's back to normal again.
Ride home was a blast after having the bike play up all day.
Thanks for all the help guys, though i'm still not sure what was going on..
I suspect the choke got stuck on. The bike has to go in and get the new fuel cock anyway, so i'll mention it to them.

Once again, thanks! =)

6th April 2006, 17:03
Well to me, it does sound like the fuel tap.

It sounds like it is blocked and is not letting enough fuel through... or blocked up carbs

6th April 2006, 21:42
Well, bikes going in tomorow. So hopefully the mystery will be solved!! =D
Thanks again guys, big help =)

7th April 2006, 13:12
Would seem that its the choke to me.

Anyway heres the manual for the CBR250:

Right click and save as... its 216MB.

7th April 2006, 18:19
meep, i'm capped at 60kb/s till the ninth.. might wait and see if sniper is still sending me one =)
Thanks though

7th April 2006, 23:50
Would be interested to know what ya mechanic has to say.

8th April 2006, 10:19
meep, i'm capped at 60kb/s till the ninth.. might wait and see if sniper is still sending me one =)
Thanks though

Courier has it mate, should be on its way:spudwave:

8th April 2006, 21:36
Not too sure about CBR, but my KDX does what you are talking about when it runs low on gas, turn the tap onto reserve and fixes.

8th May 2006, 11:24
Thanks sniper, i got it. Sorry im a bit late on the reply. heh ^^
Anyway, bike got fixed, they replaced the tap, fiddled about with other stuff and generally made it "better".
It goes, i'm happy.

8th May 2006, 11:26
Good work mate