bdoneen My Ride Posted March 28, 2010 just jetted my 09 yz250. it has the fmf sst pipe and powercore 2 silencer. geared down a tooth to 51. rode the bike for a couple hours. not super hard, few hill climbs. didn't get a chance to do a chop test with a fresh plug cause of a flat tire. my jd jetting kit had me do the red needle at 3rd position. pilot at 45 and main at 172. heres what my plug looks like after. looks lean to me right, but what do i change here? all 3 or just one or 2? Share this post Link to post Share on other sites
bdoneen My Ride Posted March 28, 2010 ok so i put the red neeld to the 4th position, thats up one spot. put on a 48 pilot and 175 main. didn't have time to test but what do u think? Share this post Link to post Share on other sites
KX02 Posted March 28, 2010 Looks too rich to me, my plugs come out a light tan color. Share this post Link to post Share on other sites
bdoneen My Ride Posted March 28, 2010 really? doesn't the burnt white part mean lean? Share this post Link to post Share on other sites
KX02 Posted March 29, 2010 That part is white when the plug is new. The whole bottom area should not be black like that. Share this post Link to post Share on other sites
Greg Y Posted March 29, 2010 this will help. color is not always the best indicator, depending on fuel, it can change a good bit. shadow and wash are better indicators http://www.snowtechmagazine.com/articles/2001/baseline/baseline.php Share this post Link to post Share on other sites
bdoneen My Ride Posted March 30, 2010 so is it rich or lean? Share this post Link to post Share on other sites
bloodline Posted March 30, 2010 I wouldn't gauge anything off that plug if it was removed from the motor after cruising back to the truck. You might be rich at idle and lean on top, which is what I suspect. Get the idle jet right and then do plug chops to get the high speed sized properly. Share this post Link to post Share on other sites