YZ426 Sand in Carb?


7 replies to this topic
  • Trbotime

Posted January 03, 2008 - 08:44 AM

#1

Any ideas on how sand can continually get into the bowl of the carb? The filter has no tears, the intake boots are are good and there is no sand in tanks. Can the carb create a vacuum effect when the bike is running?

Problem I am having is the bike will pop at idle and when you crack the throttle, then it will run badly until you get mid range in the RPM's. I'll be riding the bike and it will run good up top then when I let off the throttle the bike dies out. Anyone have any ideas on what this could be?

I have changed almost all the gaskets and grommets in the carb, so I'm at a loss here. Any help would be appreciated.

  • grayracer513

Posted January 03, 2008 - 10:33 AM

#2

What kind of bike are we working with here?

  • Trbotime

Posted January 03, 2008 - 11:50 AM

#3

Ummm from the title it looks like it is a YZ426, yeah an 2001 YZ426! :banghead:

  • grayracer513

Posted January 03, 2008 - 02:16 PM

#4

The sand comes from the fact that the choke circuit in an FCR carb draws its fresh air in through the vent tubes instead of the air horn like it should.

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

Posted January 03, 2008 - 04:17 PM

#5

First off thanks for the response. What tube is it that sucks in the sand, the one going into the bowl? So what would be the best way to stop it from sucking in sand? Redirect it or put a filter of some sort on it? Sounds like the carb may be sucking in sand and then clogging up the pilot jet making it run poorly on the bottom.

Sorry I'm so ignorant, I'm a honda guy and am only used to valve issues, not sand sucking issues. J/K no issues for me w/ valves.... Yet???

  • SXP

Posted January 03, 2008 - 04:30 PM

#6

First off thanks for the response. What tube is it that sucks in the sand, the one going into the bowl? So what would be the best way to stop it from sucking in sand? Redirect it or put a filter of some sort on it? Sounds like the carb may be sucking in sand and then clogging up the pilot jet making it run poorly on the bottom.

Sorry I'm so ignorant, I'm a honda guy and am only used to valve issues, not sand sucking issues. J/K no issues for me w/ valves.... Yet???


http://7602racing.com/prod_t6cf.php

  • grayracer513

Posted January 03, 2008 - 05:26 PM

#7

All five of the hoses running from the bowl do (that's where they all come from, by one route or the other). Fold a piece of foam over them and tape it on if it's a problem. At the least, the one that runs from the center of the bowl down must be routed downward. The highest two can go in the air box, but you should filter them, too.

  • Trbotime

Posted January 04, 2008 - 08:37 AM

#8

Thanks again Gray!





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

The "going back to the other darkside" adventure... by Monk


Dirt Bike   Make / Model Specific   KTM   250/350/450/505 SX-F & XC-F (4-Strokes)
  • Hot  113 replies
Forums
Photo

Megabomb Fitment by 288yz450


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply
Forums
Photo

BIGBORE FOR YZ450F 2006? by Taattie94


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

2016 YZ450 by CaptainKnobby


Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 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.