Proper Jetting for 05 YZ450

2 replies to this topic
  • timvan

Posted February 01, 2005 - 07:16 AM


Bike is ridden at 1k' above sea level....has a bit of poping under decel (air leak in pipe?)

The bike is completely original...where should my jetting be at?



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

Posted February 01, 2005 - 08:31 AM


I went one notch richer on the needle and backed out the fuel screw a bit(1/8th). It helped.

  • WRookie

Posted February 01, 2005 - 08:11 PM


It has been from 35-45F temp here. I ride around 5000 ft. I had some backfiring going from 3/4 to 1/2 throttle so I changed to the 170 main. From 1/2 to no throttle cackled so much I thought I was dragging Janet Reno behind me. Talk about ugly. This was at 3 turns out with the stock 45 PJ. Switched to a 48 at 1 3/4 turns out and now have easier starting and only the occasional bark.

Still haven't needed the hot start.

Related Content


YZ450F 03 Sparks driving me crazy by SirAttard

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

Michigan Motocross Tires by 288yz450

Dirt Bike   Dirt Bike Regional Discussion   North
  • 1 reply

2016 YZ450 by CaptainKnobby

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies

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

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