Help!! Engine rough at steady speed - 02'WR

5 replies to this topic
  • sticky

Posted May 06, 2002 - 02:45 PM


Anyone have any ideas on how to fix this problem. I've tried jetting up and down on the main, all clip positions on the needle (slightly effects where the burble is in relation to the throttle position), and i've tried a leaner pilot. NOTHING made it close to going away. Kinda sucks that Yamaha would ship the bike this way. I know I'm not the only one with this problem from previous posts. Getting a little tired of working on my NEW BIKE more than riding it.

Thanks for your help

  • racemile

Posted May 06, 2002 - 04:09 PM


I had the same issues. My jetting is radically leaner than any shop out here suggests, but, while i still have some of the burble, I dont notice it at all when I ride. The power it puts out now is exceptional. just a suggestion, try leaner than you ever thought reasonable and then bring it back into line based on performance and starting


  • robswr426

Posted May 06, 2002 - 04:45 PM


i timed mine to yz more problem

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  • Taffy

Posted May 06, 2002 - 11:03 PM


copy the jetting in my siganiture. if you run an open pipe go to 155/158 main. that's it.

if you have a mid throttle burble you need to drop the needle once at least but probably twice.

this will richen your PC by the equivelant of one PJ. so if it's good and you USED to like the low end but now it's rich.... go down one PJ.


  • sticky

Posted May 07, 2002 - 01:16 PM


Thanks, I'll try these settings and let ya's know. Anybody ever try changing to the stock YZ needle??? I assume this is a richer needle, right? If ya did try what did you find? Well, gonna go mess with the carb again and get ragged on for smelling like gas later.


  • Taffy

Posted May 07, 2002 - 08:54 PM


we've just had Hick come over here and throw in a grenade and tell someone to go to an ELP needle which i take it is a YZ needle for 01 or 02 but not sure and don't care.

get an N needle or an M needle. the P needle has a flat spot. go search back 30 days to "jetting Qs" by funktree. this has clear tests on the M and P needle and the P has a flat spot off of idle.

the trouble is, i've done these tests properly but one or two people haven't and are surmising.



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