2012 yz 450 EFI issue

5 replies to this topic
  • mike82

Posted September 17, 2012 - 03:06 PM


Hey guys, My bro bought a brand spanking new yz 450 at the dealership in my country in january, its been giving him issues since june, the bike stalls, coughs, and sometimes shuts down on iddle , ONLY WHEN ITS WARM, or after a few laps on the track, has anybody had this issue before? the idiots at the dealership dont have a clue on whats wrong with it, could it be the fuel filter?, Can someone please shed some light on my problem please? We are desperate, seriously dont know what to do with the bike. Thanks in advance!!!

  • Joe_Jet

Posted September 18, 2012 - 11:20 PM


Sounds like bad fuel. Drain the tank and put some quality gas in it.

  • jnabuurs

Posted December 08, 2012 - 01:52 AM


I had the same problem when the kill switch is defective the bike will run above about 4000 rpm and not at lower rpm and it's hard to start off course. I think the factory made this so you can still ride but not below 4000 rpm.

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  • ka24s14am

Posted December 08, 2012 - 03:04 PM


My 2012 did the same thing. It would stall out at idle and would cough. I idled it up and it fixed it. The idle adjustment is on the left side under the tank(cold start knob). My buddies 2012 yz250 2smoke would do about the same until we idled it up.

  • PETE24

Posted December 08, 2012 - 04:13 PM


i just had an almost new one that did the same thing ended up being the coil

  • mx369

Posted December 30, 2012 - 04:27 PM


Just a thought, I had one act up like this. Checked for codes with tuner. Nothing. Checked coi,spark plug cap, plenty of fire. Pulled the starterknob/idle screw out and blew air into hole( about 20lbs in compressor) and cleaned the brass plunger. All is well! Try it

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