needle and clip position?
Posted 05 August 2008 - 07:23 AM
Posted 05 August 2008 - 08:22 PM
Changing the clip position on the needle will have the greatest effect on ¼-3/4 throttle openings. Moving the clip up towards the top will give you a leaner setting. I think the easiest way to understand how jetting needs to be adjusted for different temperatures and elevations is with a visual aid. Here is a jetting chart that I made/posted for another member a few days ago. This is specifically for the 2006 YZ250F. This should give you a good place to start.
Posted 07 August 2008 - 05:59 AM
Posted 08 August 2008 - 05:37 AM
Posted 08 August 2008 - 06:59 PM
Posted 09 August 2008 - 10:59 PM
What track to you race at? Are you in Southern or Northern Cal? Elevation? As far as the JD needles go, if you already have them I would give it a try. I purchased a set of JD needles several years ago for my 02 YZ426 and was very pleased with the results. The last few years I have just been using my jetting program with parts from where I work or any of my local dealers. As posted on the chart (in red), I would also recommend that you try replacing the stock #80 Leak jet with a #60.
I race at starwest in Southern California, the elevation is 1457. Im going to try out the red neddle with your exact settings, they seem to match up perfectly with my elevation/temp. the biggest leak jet I have right now is a 50 so im going to put that in for now and switch it out with the 60 when I get it.
Thanks for all the help: up:
Before I had:
Needle/clip position:JD blue needle/5th clip position
needle/ clip position:JD red needle/3rd clip position
Posted 10 August 2008 - 09:39 AM
Posted 10 August 2008 - 05:38 PM
Posted 11 August 2008 - 09:17 AM
Posted 12 December 2008 - 09:31 AM
I have a '01YZ426 that just rips, I haven't changed the jetting since I purchased the bike some 3 years ago. I wanted to verify everyone is correct on the jetting side and have been doing the research to see what I need to check and so on.
I have modified the pipe a little(Because I flipped it practicing starts.LOL) and cut about 3" off of it. I repacked it and everything looks great its just a little bit louder . I'm also running an 07 air box which directs air straight into the carburetor. Full FMF Power Bomb header and FMF Ti4 exhaust.
I've riddent the current Jetting from 30ish to 100+ degree days? I'm just wondering If I should even mess with it?