just rejetted... how do you read plugs? - Printable Version +- Madison Motorsports (https://forum.mmsports.org) +-- Forum: Madison Motorsports (https://forum.mmsports.org/forumdisplay.php?fid=3) +--- Forum: Motorcycles (https://forum.mmsports.org/forumdisplay.php?fid=10) +--- Thread: just rejetted... how do you read plugs? (/showthread.php?tid=8291)

just rejetted... how do you read plugs? - BLINGMW - 06-30-2009 Installed a K&N filter and rejetted to match. Bike runs great. But I'd like more confirmation that the mix is right. If I understand correctly, the correct way to make sure the mix is right at full throttle is to warm it up, go full throttle/load for a few sec and cut it off. Coast to a stop, read them then. But I have to say, I have a real problem doing that intentionally. The valves are at their hottest then, and I shut it down? I really hate doing that. So what I did.... full throttle for 3-4 sec in first up the road to my driveway, hit kill switch and clutch, close throttle, roll into my driveway. As I roll down the driveway, shift to 2nd and let out clutch. Then the motor gets to turn over a few times without actually running. Is that valid? So far my plugs turned out white before and after the rejet, so either I was lean then and am still lean now, or my test method sucks. :dunno: How fast does plug color change? Is 3-4 sec even enough? Is it safe to say that looking at plug color any other time is really just an indicator of the mix at idle since it probably idled before shutdown? This voodoo doesn't satisfy me, I want a wideband. :? Re: just rejetted... how do you read plugs? - .RJ - 06-30-2009 As long as the motor isnt running its fine to let it turn over - I like to use a longer pull than 3-4 seconds though, WOT uphill, 3rd/4th gear is best - on your 500 you might even break the speed limit :lol: I'd also start with a new set of plugs.... did you take a picture? Re: just rejetted... how do you read plugs? - BLINGMW - 06-30-2009 yeah a longer run would certianly make sense... I guess I could just check them by the side of the road, cause blasting up our little private road would make my neighbors super happy. I didn't take a pic and didn't start with new plugs, no. I'd say it looked like this pic's "normal", but a little whiter though I don't know why that pic has "normal" as white. Most describe and show more of a tan color. Whatever. Maybe my test is good and it's just a touch lean. :dunno: dyno time