hello i have a 1998cbr 900rr and sudenly didnt start at all,i change the spark plugs and still same,battery is seem ok,i took it to charge it and it seem the bike will start but it doenst,i try turn it on while crank the trothle and it does start but it doenst stay idle,im wonder what its wrong,any sugestions ?thank u.

 

Make sure your gas valve is on (left side of bike, switch or circular ***). Does the starter turn over and slow down? Does it click?

 

check that all the spark plugs are plugged in all the way- You did unscrew the screw-on heads of the spark plugs didn't you?
Also, check that the wires are going to the correct plugs- The wires are marked with what cyl they go to, and the cyl #'s are right on the valve cover.
Check to see if you are getting spark by grounding a spark plug against a known ground on the bike, and turn the engine over.
do you smell gasoline? is there fuel getting to the carbs?
is the engine flooded?

I know it sounds like a lot, but that's because there could be one of many things, or a couple of things working against you

air

fuel

spark

You need these three things, and the engine will run. if you didn't touch a thing on the bike, then you are missing one of these things. test to eliminate problems, or systems, then it will lead you to the problem.

and…… GOOD LUCK!

 

thanks guys tomorrow i will check the spark plugs i just pout them all 4 brand new,i just add some seafoan earlier and i charge the battery,how can i check if i got spark,should i take the cap out and put the splug inside then touch the frame that thing works,the cables are ok becos they have they own number ,i will tak them off then do it again i mean unscew them and pout them back inside ,i let u know wahts up,the bike was running amazing good just sometime i n the morning hard time to turn on becos the old splugs arent good ,too old and burn,i let u know guys whatrs going on tomorrow.thanks

 

hey exiter900rr i dont think those spark plugs (ngk rc9eh-9)have to unscrew the screw ,but im not sure i just tell u becdos i check some pics and dont seem like it,thanks

 

welll today i checked my bike again and the plugs seem fine and i got spark,i did what u toldme exiter and like i said i got spark,the only way the bike start is cranking the trothle abit then push the ignition but i let it go it dies,i think is the fuel filter but i dont know if mine has one or not,and also how to take the tank out the bike,anyone knows something about it.any ideas are apreaciated it.thanks

 

Check your idle adjustment too. May be turned Dow to low. If needed, hold throttle steady at 1k or 1.5k rpm. Adjust ur idle until you can release the throttle.

 

So the bike will try to start, it is getting air, fuel and you confirmed spark.
like paranoia said, keep it running, and adjust the idle- hopefully it's a start to find out what's going on.
Another thing to look for, is under the carburetors, you will see vacuum lines attached to brass fittings screwed into the intakes on the head. some models have spaghetti of hoses connected (california models) and others have none, and rubber plugs on them. Check them for cracks/vacuum leaks. As a matter of fact, check them first before messing with your idle too much- it may just be a vacuum leak that is making it not want to idle, and hard to start.
Sounds like you're getting close to finding the culprit!

 

hey fellas wahts up i just take the tank out and check the air filters and look ok but smell like fuel on it,also the carburater box is kinda smell of gas but the carburaters theyre not dirty much just abit arround so i clean them,i was cheking and cheking and on the top rigth corner in the airbox is a line there and that line was off and dirty so i clean it and i conected it into the airbox i hope that is the whole deal ,i think i was missing some air or something,but it was disconected it from the airbox i found the clamp on the bottom of the line and i installed it so tomorrow i will put the tank back and the other lines in the petcock and fired up see if works,im positive about it,like exiter said i was missing some air i think.thanks and i keep u guys in touch see waht going on.I forgot to mention that i try to find the fuel filter but i cpouldnnt see it at all,is 900rr 1998 i know that model dont come with fuel pump but i dont know about fuel filter,thanks again.here some pics,the first one is the line that it was out from the airbox,and u can see the tha airbox wasnt that dirty just on top abit,,thanks again.