Hi guys, i don't own a CBR trying to fix a mates one. I'm an apprentice mechanic for Audi, drive an rx7.

The Problem:
Mate was riding the bike(an 89 CBR 250cc, if you need to know more ask)and it just cut out, ie. stopped running. Now when you turn the key, the lights come on(the oil light i think it is, and the green ready?)and everything, but when you press to start the engine, nothing happens. So far i've checked the connections all in the front end, haven't pulled the entire chassis off yet, clean the connections with rust off ect, also checked the fuses and they all seemed fine. What could it be?

Thanks for any help guys.

 

Have you checked out the battery, The regulator being RS (not charging the battery). (The green light is the Neutral Indicator), He hasn't hit the kill switch by mistake?. Maybe the bike was originally from Sydney & can't stand Melbourne traffic . There is a European section that has the 125's & the 250's that could be more specific for your problem. Good luck

 

HAHA Nah it's all good now man, yeah i forgot to say i checked the battery. Found out it's a vacuum leak, one of the vac hoses had those crappy clamps and had dropped off. So all good now, $100 for fixing a vac leak.

And i can honestly say Syd drivers are worse than Melb. I go sydney one week a month for work, and the drivers there are shocking. Weaving between lanes, cutting off people, indicating after changing lanes. Scary stuff. :S Melbourne just has stupid drivers, not bad ones. LOL

 

Mate those Melbourne hook turns freak me out. You know who all the bad Sydney drivers are don't you? Melbournians moving up to the Gold Coast. Anyway glad you got it scoped.

 

Update: seems its more than the vac leak... I got it running, but as soon as it warms up and you give it any throttle, the thing dies out. Any ideas?

 

Wot state of tune is it in? Could be carbs related, they may need to be tuned & synched, could be a blocked/dirty air filter. So it starts up with choke & then dies after its warmed up & when you blip the throttle?

 

Yeah the filter is all good checked that. Was starting to think it was carby related, one thing i aint so knowledgable about. But yeah, when cold it revs fine, throttle is perfect, but after it warms up, any throttle and it just dies out. Where are the mixture screws on the carby? :S

 

There usually at the sise of the carbi, not to sure about the 250's but, should be the same. don't want to throw could water on your abilites here, but synching the carbs is not for the faint hearted & your going to need some synch tools to do it. I suspect that it is the carbs, but just check the rest of the hoses to be sure before taking that next step. May be you need to put the bugger in the shop.

 

Is it one or two mixture screws on a bike? And an idle screw too right? Am i able to just fool around with the mixture screws until i get it right or is that a no no? It's not my bike so i'm trying everything i can before i tell him to take it to a shop.

 

Its usually done using a synch meter (so they all work at the same time) & the mixture screw(s), but like I said before, it ain't easy. different with a single carbie, when you go by sound etc, but with 4 going off at once its hard to pin down which is the ones giving you grief, & you can end up with all of em out. It ain't that much of a biggie as far as $'s go at the shop, once their done they run sweet for ages.Could even end up being jets or whatever as well. Lot of things can make the bike run like it is now. But a decent mechanic should be able to sort it all out for you. Must be some good ones still left down there?