is it still a fuel screw?

3 replies to this topic
  • thelimey1

Posted October 09, 2004 - 09:51 PM


bought my daughter a little no name 90cc four stroke dirt bike, (cos it was blue) the idle mixture screw is back at the rear of the carb, right by the air filter boot, instead of near the engine side, is it still a fuel screw, or would it be an air screw. sorry for the stupid question. :cry:

  • sirthumpalot

Posted October 10, 2004 - 02:44 AM


Not a stupid question, but very difficult to answer without knowing what carb it is. Play with it a little; if you unscrew it and it gets richer then it's a fuel screw, if it leans out then it's an air screw.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Fastest1

Posted October 10, 2004 - 08:12 AM


Most small 4 strokes dont run an accelerator pump and are using 2 stroke carbs. If the screw is between the carb and airbox, it is an air screw. If it is between the carb and cylinder, it is a fuel screw.

  • thelimey1

Posted October 10, 2004 - 06:34 PM


thanks muffins, preciate the fast response. you would think it would be obvious if i fiddled with it, which im prone to do, but its so underpowered and poorly tuned, it hardly makes a diff.

Related Content


James Stewart back on a YZ450F by YamaLink

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies

yz250x vs 450 4t comparisons (preferably desert riding) needed by JakeNorthrupYZ450F

Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • 9 replies

Thinking about Yamaha 250... by Arctic Pride

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 replies
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info

  • 0 replies

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

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.