04 yz450 backfiring ,not starting sudenly

2 replies to this topic
  • steveyz450f

Posted May 17, 2008 - 01:44 AM


four weeks ago my bike started to backfire and wouldn't start, previously it was running real good but it has been getting harder to start over a period of time, so i took it to the shop(valves, shims done, carb air mixture adjustment) so i took it out for a spin today, i noticed that it back fired 5-7 times but it did fire up alright and idled for 3-4 minutes or so. one minute into my ride it smoked alot and lost alot of power, so i bought it home and tried to start it, and back to square one, it just back fires and wont start again, the only things I've done to it is a new plug, cleaned air filter and the right amount of oil, any info before i take it back to the shop , please please

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  • tf705

Posted May 17, 2008 - 08:58 AM


it sounds like your timing off. maybe your timing chain skipped.

  • steveyz450f

Posted May 18, 2008 - 12:51 AM


i forgot to add,4 weeks when it suddenly packed up i found under the tank right next to the coil(black box) there is a white wire about inch long, it looks like a earth wire that goes nowhere, looks cut, another thing i did see is where the wiring loom go into the motor in the cdi i notice-st water coming from the electrical tape so i started to unwound the tape and around a 1/4 cup of water come out of it, when i think back the last thing i did was wash the bike and i did put the hose under the tank, im not sure if that's going to be anything. thanks for any replies. sorry im not very mechanically minded

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