04 yz450f dies during acceleration


4 replies to this topic
  • usmc_brianw

Posted September 05, 2010 - 07:53 PM

#1

Today my 04 yz450f died multiple times doing exactly the same thing. Rode trails, hill climbs, technical, and some faster sections, no problems, runs great. Get down to the main dirt road open it up, cruising in 4th dies after about 3-5 minutes, every time. The bike accelerates fine otherwise, no hesitation, does everything I ask of it. When it dies it's like hitting the kill switch. Won't restart for about 5 minutes, at all. I read some other threads about similar issues. Ideas where to start? electrical, fuel issue, carb issue, vapor lock? Thanks in advance for any help.

  • gscx

Posted September 05, 2010 - 07:57 PM

#2

Your float bowl is running dry, reajust your float height

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • grayracer513

Posted September 05, 2010 - 08:07 PM

#3

Inspect the gas cap. Remove it and separate the vent hose from the in-line check valve. With just a hose connected to the cap, you should be able to blow air into the vent fitting and through the cap fairly easily, and find it more difficult to draw air through from the cap in the reverse direction. Test the check valve in the same manner. You'll find an arrow embossed on the valve, and air should flow in the direction it points. Be sure it point to the cap when you put it back together.

If it quits again, try unscrewing the cap and listen for a rush of air into the tank. If you hear that, and loosening the cap makes it able to restart immediately, you have a vent problem.

If it doesn't "fix it", you may have a clogged filter screen on the petcock.

  • usmc_brianw

Posted September 08, 2010 - 09:10 PM

#4

Inspect the gas cap. Remove it and separate the vent hose from the in-line check valve. With just a hose connected to the cap, you should be able to blow air into the vent fitting and through the cap fairly easily, and find it more difficult to draw air through from the cap in the reverse direction. Test the check valve in the same manner. You'll find an arrow embossed on the valve, and air should flow in the direction it points. Be sure it point to the cap when you put it back together.

If it quits again, try unscrewing the cap and listen for a rush of air into the tank. If you hear that, and loosening the cap makes it able to restart immediately, you have a vent problem.

If it doesn't "fix it", you may have a clogged filter screen on the petcock.

The check valve was the culprit, what a relief! Thank you much for the reply.

  • grayracer513

Posted September 08, 2010 - 09:40 PM

#5

Semper Fi :ride:





Related Content

Forums
Photo

James Stewart back on a YZ450F by YamaLink


Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies
Forums
Photo

YZ450F 03 Sparks driving me crazy by SirAttard


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 5 replies
Forums
Photo

Is it worth it? (Cam and High compression piston) by macgi77


Dirt Bike   Make / Model Specific   Honda   CRF 150/230 F/L
  • Hot  36 replies
Forums
Photo

100 hrs on 2014 yz450f, shim valves or replace them? by ttr230rider6


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  79 replies
Forums
Photo

Snake pit oct 30th by The Anvil


Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 replies
 
x

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.