'03 YZ450 jetting questions.

2 replies to this topic
  • John407

Posted July 09, 2006 - 09:48 PM


I installed an exhaust insert in the Akropovich exhaust on my '03 450. The noise is down but it is still running rich even after I went right to the top clip on the needle.
The needle is a NVCQ what is the next leaner needle?
The main is a 165 S, is a 160 the next leaner main?
The pilot is a 42, is a 40 the next leaner?

Thanks guys.

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

Posted July 10, 2006 - 06:35 AM



  • John407

Posted July 10, 2006 - 09:54 AM


I appreciate the quick response but the answer to "what is the next leaner needle to a NCVQ" can't be yes, can it? I searched a little more and I think there is a 162.5 main inbetween the 165 and 160 and the needle goes alphabetically. The first three letters refer to the taper and the "Q" in this case is the "leanness" ie: an "R" is richer and a a "P" is one step leaner. If I got this wrong pleas let me know, Thanks again.

Related Content

WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info

  • 0 replies

Thinking about Yamaha 250... by Arctic Pride

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 replies

Help with 2000 yz426 by weekend woods racer

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  36 replies

Michigan Motocross Tires by 288yz450

Dirt Bike   Dirt Bike Regional Discussion   North
  • 1 reply

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

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.