so i have a 98 cbr900rr and i was going to winterize it and the battery was dead so i charged it and it wouldnt start and after a couple tries it made a loud popping sound like it back fired what could be wrong and how do i solve it?

 

It could be that your battery just doesn't have adequate juice to fire it correctly.
Does it sound kinda weak when you crank it?

 

The pop through the exhaust is a sure sign the plugs have fouled.

If you didnt let the battery fully charge and you cranked it over, the plugs are probably fouled. So, if you had a couple of attempts while the bike was cranking to slow to start, thats the issue. You may be able to let it sit for day, with the battery fully charged, try it again. Or, you may end up having to pull the plugs and replace them, depending on how flooded they are. Also, do not add throttle as you are trying to start it in cold temperatures.

Keep in mind the iginition systems on these bikes are very weak. Thats partially the reason you need the battery fully charged and the bike needs to crank over fast, otherwise, they flood. That in combination with the cold temps, just makes it worse.

 

ok so i let the battery charge overnight the charger said it was full and when i went to go start the bike a little flame came out of the end of the exhaust. what is going on and how do i take care of it?

 

turn fuel off or disconnect fuel pump (not sure if that model has a petcock)... hold wide open and let it turn over for a few seconds. Then reconnect/turn petcock on and try to start. do not turn the throttle while trying to start.

did you mess with the spark plugs ? what was the last thing you did to the bike (prior to problems)?

 

before the problem i was out riding and it sat for 3 days without starting it but it was running perfect. so what about the flame that came out of the exhaust is that ok?

 

Had a very similar problem two months ago. I knew my battery was good, so I did the logical thing and started with the plugs. they looked a little fouled so I replaced them ($80 later). Tried starting again, no dice. then performed a spark test, (take out a plug, reattach it to a coil pack, and see if there is spark) In my case I had spark, but still no ignition. Began to think: 4 things needed for engine to run: fuel, spark, air, and compression. Based on the gas I could smell, I knew it was getting fuel, so I replaced the air filter, and did an inspection of the air intake at that time. Hoping, (after that failed), that it was not a compression issue, I began to think the problem was ECM based. I was ready to take it to a dealer at that point thinking the problem was beyond my troubleshooting abilities...

Then out of the blue I had the crackpot idea of blowing compressed air into the intake while trying to start it, and Bingo! She fired right up! had to massage the throttle a bit for a while, but let it run until it blew whatever foul carbon and crap was gone.

I then adjusted The IDLE SCREW properly to the correct RPM at idle, and have not had an issue with it since! My assessment (sp) was that the idle screw had come out of adjustment and wasn't giving her the fuel she needed at start up.

Hope this lengthy story will set you on the path to recovery!

 

I still say the plugs are fouled. At this point, I would just change them with new ones. Once these little plugs foul, they are pretty much done for. You can try to pull them and dry them out, but from past experience, you'll be replacing them anyway as they will foul extremely easy from that point on.

The flame out the exhaust is more than likely due to the plugs being fouled because: since the plugs were not igniting the fuel so it just dumped into your exhaust. So, you have an exhaust full of gas and fumes, then one sparkplug can fire randomly, and all of sudden, you have ignited the gas inside the exhaust. It wouldnt have hurt anything, but you need change the plugs.

While the plugs are out when your changing them, crank the engine over a few times to clear out the gas that may still be built up in the cylinders. This will also help exhaust the gas that may be built up in the air box. When a bike is not firing, the gas reverbs back into the air box as well.