cals400ex
04-03-2004, 01:50 PM
well i have found a couple fairly long jetting threads for the fcr carbs. i have seen several people on here lately ask for jetting help with their new fcr carbs (including myself :D ). i am just wanting to be a little more specific than some of the other threads to help get these tuned in a little better. lets get started:
1. main fuel jet size
2. fuel skrew position
3. what needle
4. needle clip location
5. air skrew position
6. main air jet size
also, a brief overview of your motor mods, temperature its jetted best for, and your elevation if you know it. also, here are a few links to help tune your fcr and the other link is for the accelerator pump mod to eliminate the low to midrange bog. the normal accelerator pump will shoot fuel for somewhere between 4 and 6 seconds. this can cause the bog for our 400ex engines. i reduced time frame of the squirt to about .5 to 1.0 second. here are the threads:
http://www.exriders.com/vbb/showthread.php?threadid=49845
here is some fairly complex tuning guides for the fcr:
http://www.factorypro.com/tech/carbkei.html
1. main fuel jet size
2. fuel skrew position
3. what needle
4. needle clip location
5. air skrew position
6. main air jet size
also, a brief overview of your motor mods, temperature its jetted best for, and your elevation if you know it. also, here are a few links to help tune your fcr and the other link is for the accelerator pump mod to eliminate the low to midrange bog. the normal accelerator pump will shoot fuel for somewhere between 4 and 6 seconds. this can cause the bog for our 400ex engines. i reduced time frame of the squirt to about .5 to 1.0 second. here are the threads:
http://www.exriders.com/vbb/showthread.php?threadid=49845
here is some fairly complex tuning guides for the fcr:
http://www.factorypro.com/tech/carbkei.html