Dirty Carb


1 reply to this topic
  • WGP

Posted September 05, 2008 - 09:00 AM

#1

I pulled the carb on my 06YZ450 and everything was clean except the top of the carb?? Why is that place so dirty? It wasn't really chunks of dirt but more oily black scum:excuseme:

Is it those small breather hoses letting fine dust in the top....

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

Posted September 05, 2008 - 09:23 AM

#2

That area above the slide has air moving into it, and sometimes through it, but not much. It is "open" to the carb throat in the sense that it is not sealed off from it, and air is allowed in through a passage from the carb bore forward of the slide. That allows the slide to move freely up and down. When the hot start is opened air flows up into the area above the slide, then out the back through a passage that runs past the HS plunger and down int the intake behind the slide to add air to the idle mix. The vent tubes don't lead into this area, but run to the float bowl instead.

All of this results in the top of the carb being exposed to fuel vapors without having enough air or fuel run through it to keep it cleaned up, so it can get fairly foul looking. It usually isn't a problem though.





Related Content

Forums
Photo

05 yz450f not fast enough by RedeyeYZ


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  38 replies
Forums
Photo

2016 YZ450 by CaptainKnobby


Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
Forums
Photo
Supercross

Wilson the Blue Privateer by jetfuel


Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  50 replies
Forums
Photo

James Stewart back on a YZ450F by YamaLink


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

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
 
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.