HELP!!! 07' Electrical? Fuel? Won't run....

7 replies to this topic
  • lftdjeep426

Posted July 01, 2009 - 04:53 PM


HeyGuys..... need some help on this one. My 07' 450 won't run. Last weekend I went to ride and fired up the bike and after about a mile on the trail I was going through some sand whoops in the meat of 4th and it started sputtering and died as soon as I let off the throttle. I brought it home after futile attempts to re-fire it. I changed the plug and nothing. I pulled the carb and cleaned it and put it back in and no fire. I checked the spark and it has good spark. I checked the resistance of all of the electrical system and when I applied some dielectric grese to the connections and buttoned it back up it fired, idled and reved. I shut it off for the night. Today when I got home I put everything back together and kicked it a few times, backfired a couple of times and then fired up. I took it off idle and let it finish warming up reved it a few times (nothing excessive) and I took off down the street. about 1/2 a block it did the same thing, while I was giving it consistant throttle it started sputtering and died. Wouldn't re-fire. I brought it back in and pulled the carb and tried the carb off of my 250f and nothing won't fire. I would think it was a carb issue. I guess it could be electrical but what could it be. I'm at my witts end and have run out of answers. Can you guys help?

Figures, I just took a paycut at work so I REALLY don't want to have to take it to the shop.......

So much for getting a new bike to not have as many problems..... its got 42 hours on it and I put 38 of those on it..... Its basically stillpretty new.....

  • lftdjeep426

Posted July 01, 2009 - 08:14 PM


Any thoughts would be a great help......

  • grayracer513

Posted July 01, 2009 - 08:43 PM


Test for spark. If you have none, or it seems weak, test the stator. If the compression of the engine seems abnormal in any way, check the cam timing.

  • jeffboyd47m

Posted July 01, 2009 - 09:57 PM


Another thing that is worth checking is the spark plug cap coil. I had one go out on my bike and finally figured it out by borrowing the cap from my son's bike. If you know of anyone with a 06-09 the caps are all the same and easy to swap and check.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • lftdjeep426

Posted July 02, 2009 - 04:40 AM


can I use the one off of my 06' 250f?

  • lftdjeep426

Posted July 02, 2009 - 05:11 AM


Just came out this morning and it did it again, fired first kick, let it idle for a few minutes and I took off down the street and when I cruised into 5th 1/4 throttle it sputtered and died. Wouldn't start again? I swear this sounds fuel related but I'm pretty sure I ruled that out by trying the other carb. What electrical could be making it do this?

  • usmcpaul

Posted July 02, 2009 - 05:47 AM


Did you check the vent line?

Try this scenario on for size. It started and ran for a while until it created a vacuum in the gas tank. Then you probably took it back and shut the fuel petcock off to change the carb; thus maintaining the vacuum in the tank.

Then you installed the other carb, when you opened the fuel back up, the vacuum was still keeping it from getting fuel.

Just a suggestion, try running it with the fuel cap loose.

  • WB450

Posted July 02, 2009 - 06:59 AM


Do you have a new gas cap? Make your cap vents the tank.

Related Content


Yamaha YZ450F 2017 by Chris.GVS

Yamaha YZ450F 2017
  • * * * * *
  • 1 review
  • Last review by Tommyk_55
  • On January 15, 2017

Should I buy this bike? help....... by Numsa Hul

Dirt Bike   General Dirt Bike Forums   What bike should I buy?
  • * * * * *
  • 10 replies

James Stewart back on a YZ450F by YamaLink

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies

2016 YZ450 by CaptainKnobby

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies

Chubby dad, looking at bikes , First trip to the orange/black forum ! by Slow_ride

Dirt Bike   Make / Model Specific   KTM   250-530 EXC/MXC/SXC/XC-W/XCR-W (4-Strokes)
  • Hot  28 replies

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.