What series pilot??

2 replies to this topic
  • Uponone420

Posted April 23, 2009 - 05:07 AM


Hey guys, I know when you start a new thread, you suppose to search first. I did this and I found my answer, unfortunately I forgot it and can't find it again. The question is what series pilot is in the FCR Keihin 39. I believe it is a 21 series. Also since I'm being lazy/efficient can anyone tell me the stock needle position. Just bought a 450 and who ever jetted it has it runnin 178 main at slightly above sea level! Therefore I have reason to believe the rest of the carb is screwy. Thanks for yalls time

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

Posted April 23, 2009 - 08:20 AM


What year is the bike?

Yes it is a series 21 pilot jet.

178 sounds a bit oversized.....

Check the Jetting Data base for some help with specific jets to use. There is tons of great info in the link below.


  • Uponone420

Posted April 24, 2009 - 05:56 AM


Its an 06. I agree it is really rich. I am going to go with a 48 pilot and 168 main. Dont know about needle clip yet. Picked the bike up bout a month ago.

Related Content


2016 YZ450 by CaptainKnobby

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies

Michigan Motocross Tires by 288yz450

Dirt Bike   Dirt Bike Regional Discussion   North
  • 1 reply

Thinking about Yamaha 250... by Arctic Pride

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 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

YZ450F 03 Sparks driving me crazy by SirAttard

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 5 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.