[Chewy]

Hi everyone. So I recently just brought a CBR250RR, I brought a new battery tried to start it but the motor won't start, it turns over. Dad and I looked in the carby and it's dried, we put petrol just the day before and not even a drop in the carby, apparently the bike has been sitting in a garage for 2-4 years without been turned on. We poured some petrol down the Inlet and it still didn't start. It backed fired once or twice, just today the motor started half a second. My Lights, Blinkers, break light etc turn on. I don't know what to do.

 

[Lane]

Strip and clean the carbies paying careful attention to all the brass jets and emulsion tubes and new plugs.

 

[Qtr Horse]

Lots of helpful information here:
https://cbr250.com/forums/cbr250-forum/56-official-"my-bike-wont-start"-thread.html

Any changes you make, do them one at a time.

 

[ekaftan]

The fuel petcock is vacuum operated. If the carbs are dry its going to take some time to get it running. Just pull the choke out and crank it for 10-20 seconds and then wait a minute for it too cool down. If all is fine it will start.

If it does not... a carb strip and clean is required.

 

[AngieBaby]

Persevere! You got her to run for half a second your laughing she’ll go.. battery needs to be nearly full charge to have enough crank to get her going. Even if it sounds good, sometimes mine won’t run until I chuck the jumper leads on if she’s sat a couple of weeks. Then she fires up right away! Screw the air intake knob open just a little ( near your left knee) or try adjusting that up n down gradually till she sounds like she wants to go! I always have to open mine till she warms up a bit, then she revs to hard n I turn it down..

 

[vitamine27]

where do you live? if you're in melbourne I can give it a carbie clean and get it running,

don't pour petrol down the inlets, tiny pistons taking tiny gulps of air, you just drown the plugs,

fill the carbs with a plastic sauce bottle of petrol,

heat up some aerostart, and give it small whiffs of it, do it with jumper leads on rather than flattening small battery

 

[Gromit]

Only sure way is to completely clean the carbs. If you can find someone with an ultrasonic cleaner it will make life easier. Old petrol forms a sticky gum and blocks tiny passages. Carb cleaner may help but a full clean is best. While you're at it, strip and clean the sidestand switch too.