Fuel screw o-ring

5 replies to this topic
  • Goosedog

Posted October 09, 2006 - 05:36 PM


As my search for ways dirt is getting into my carb I looked thru the owners manual tonight for things in the carburator diagram that I might have missed. The picture of the fuel screw shows a spring, small washer and finally a tiny o-ring on the needle end of the screw.

I had installed a Zip-Ty fuel screw a few months back and might have lost that o-ring on the end because I didn't remember one there and I just backed it out to check and there's only the spring and washer. Could that missing o-ring be letting in enough grit to keep fouling my jetts?

  • Blue4Ever

Posted October 09, 2006 - 05:58 PM


Goosedog, The o-ring may still be in the opening. Try looking up in there, and if so use a DULL pick tool to pull it out. It will not foul up your jets but will allow additional air in the slow curcuit, causing a mild lean issue.

  • 642MX

Posted October 09, 2006 - 06:05 PM


2 ways dirt gets into the carb. 1. Crap in the gas. 2. Its sucking it in thru the air filter.

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  • YZ426F Rider

Posted October 09, 2006 - 08:09 PM


Are you 100% sure it's dirt? Could it be that your air filter is disintegrating and that's what you are finding?

  • Goosedog

Posted October 10, 2006 - 03:51 AM


Are you 100% sure it's dirt? Could it be that your air filter is disintegrating and that's what you are finding?

Yeah, It's hard and gritty...definately not foam pieces.

  • YZ426F Rider

Posted October 10, 2006 - 07:31 AM


Hmmm...I'm going to assume that you checked all the obvious things off the list like:

-filter grease on the filter/airbox mating surface
-ensured that the filter has a tight fit around the filter cage where the mounting screw goes in and are using the washer.
-refueling container is clean
-fuel tank is clean. Can you see to the bottom...probably not, did you pull it off and make sure it is spotless?
-is your airbox clean? Could you be knocking dirt in when pulling the airfilter?

Have you tried a fuel filter to see if anything gets picked up from the tank?

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