03 yz450 not starting for first time

9 replies to this topic
  • dirtman22

Posted September 01, 2007 - 08:44 PM


hey guys i went out to start my 03 yz450 today and it never started. This was very different from normal where it starts within the first 2 kicks every time. I have yet to replace my spark plug since owning it, but ive heard its a pain in the but so i dont want to do that untill i know its the plug for sure.

Some things the bike was doin:
1) After kicking several times smelled gas from exhaust
2) Really loud backfire on a few kicks

and cant think of anything else right now

  • Ga426owner

Posted September 02, 2007 - 05:22 AM


Sounds fuel related or carb issue but could also be valve adjustment time

  • go_speed

Posted September 02, 2007 - 05:26 AM


my 426 did it friday. put new plug in. second kick fired right up

  • dirtman22

Posted September 02, 2007 - 05:42 AM


yea it sounds like the bike is choking trying to start it not getting fuel or air but then when i kick gas fumes come out of the exhaust. Could this have anything to do with the fuel screw and where its set.

  • Quack

Posted September 02, 2007 - 03:05 PM


Replace the plug, it will prolly start then. Yes it is a bugger to do, but really it isnt all that hard if you are at home and have a few tools. I had to change mine at a track and didnt have tools. Still only took like 15 min, and that was my first time.

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  • dirtman22

Posted September 02, 2007 - 06:12 PM


ok ill replace the plug, have to wait till tuesday to pick one up, and ill see how that works. I tried to start it again today and it actually started for about 1 sec and then died with a really loud backfire, does that hopefully sound spark plug related??

  • kevin204

Posted September 02, 2007 - 06:27 PM


Probably, I had a Yamaha 250F that was doing basically the same thing, and putting in a new plug solved it.

  • 695

Posted September 03, 2007 - 04:42 AM


What is the LAST thing you did to it ? change air filter,oil or anything double check you work there first. Have never changed the plug !!!!! well regardless it needs a plug.

  • dirtman22

Posted September 03, 2007 - 01:30 PM


haha no ive never changed the plug, i should have said it differently though, Its an 03 but it was stored and never ridden until last winter so it hasnt been a year yet on the plug, but it would have probably been time for a change anyways. Im just hoping the spark plug is the problem.

  • Quack

Posted September 03, 2007 - 02:55 PM


Mine acted just like yours, I replaced the pplug kicked it twice, and all was good.

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