QuestionHi m8. I have a 2002 CBR 600 Fsport which has given me no grief in the 2 years I've had it..until now. On start, I hear the fuel pump prime, and the starter turns, but no fire. It bump starts and runs smoothly, but won't fire from the starter. I heard it said that a weak battery might be enough to crank it, but not to feed the injectors. My next step was to charge the battery,but although it spins faster than I've ever heard it: no fire. HELP!
AnswerJohn, I reckon you are in the right area for the problem, the starter spins better now, and turns the engine over pretty well, are the plugs looking damp, or wet, i.e. there is fuel getting in there via the pump, I would surmise there is, and if it is bump starting OK would suspect the actual spark intensity. You can see that bumping allows all the available electrical power to be be relayed to the coils/plugs etc. so bigger healthier spark. When the starter pulls it's juice to turn, there is less left for the ignition system. Remember, it's the amperage we need for the ignition primarily, not the volts. Can you get a tester for the battery, and test the amperes, older batteries don't hold as good amps as a new one of course, the volts will prob look OK on a test, but it's the amps you need.
Can you try a known good battery instead of your one? Although, If you get a tester and it shows poor amperage, you will know it is the battery anyway
