YZ426 Sand in Carb?

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.

What kind of bike are we working with here?

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

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.

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???

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

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.

Thanks again Gray!

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