the magic rule of jetting, lol, be willing to exparament with jets! some knoledge i recieved was you are jetting your mechine on a day-to-day basis; that is depending on humidity, altitude, and temp. if one changes it can throw your mechine off, but overall just change out your mains as needed, or wanted if you feel like messing with it

 

i went with a .155 and i thought it was starvin for gas on top end , so i went up to a .172 and it wouldnt run for anything , so i went back down to the .155 ,i couldnt tell much differencewhen i bored mine , im missin somethin some whereon mine , the guy before me gutted the white br slip on & im startin to think that is part of my problem casuse it aint got any back pressure

 

Why on earth did you go from a 155 straight to a 172??? The only way you would do that is if you had it on a dyno with a sniffer to see the a/f ratio.

 

thats what the guys @ the shop told me , they said it should b closer to .180 so i tried .172 , but when i checked the new plug it looked tan , not white , or black , but it wont run

 

Wow that's weird that they would tell you that without putting it on a dyno. These are Keihin jets right? Maybe they were getting confused with dyno jet numbers. I know a dyno jet 180 is the equivalent to a Keihin 202.

 

tan is what you want for plug color... i was told that Khein#'s mikuni#'s and dynojet#'s are diffirent. cant find any khein chart, but mikuni-dj #'s

<a target=_blank class=ftalternatingbarlinklarge href="http://www.ds650.net/mikunivsdynojet.htm
">http://www.ds650.net/mikunivsdynojet.htm
</a>

most OEM carbs, mikuni, #there jets in flow rate mer min. dj uses size of hole...

but i was beaten!

 

They are all measured by diameter. Here's a chart
Width------Keihin # -- DynoJets # -- Mikuni #
0.0350---- 92.5--------- 92----------- 86.3
0.0360---- 95----------- 94----------- 88.1
0.0370---- 97.5--------- 96----------- 90.0
0.0380---- 100---------- 98----------- 91.9
0.0390---- 102.5------- 100---------- 93.8
0.0400---- 105--------- 102---------- 95.6
0.0410---- 107.5------- 104---------- 97.5
0.0420---- 110--------- 106---------- 99.4
0.0430---- 112.5------- 108--------- 101.3
0.0440---- 115--------- 110--------- 103.1
0.0450---- 117.5------- 112--------- 105.0
0.0460---- 120--------- 114--------- 106.9
0.0470---- 122.5------- 116--------- 108.8
0.0480---- 125--------- 118--------- 110.6
0.0490---- 127.5------- 120--------- 112.5
0.0500---- 130--------- 122--------- 114.4
0.0510---- 132.5------- 124--------- 116.3
0.0520---- 135--------- 126--------- 118.1
0.0530---- 137.5------- 128--------- 120.0
0.0540---- 140--------- 130--------- 121.9
0.0550---- 142.5------- 132--------- 123.8
0.0560---- 145--------- 134--------- 125.6
0.0570---- 147.5------- 136--------- 127.5
0.0580---- 150--------- 138--------- 129.4
0.0590---- 152.5------- 140--------- 131.3
0.0600---- 155--------- 142--------- 133.1
0.0610---- 157.5------- 144--------- 135.0
0.0620---- 160--------- 146--------- 136.9
0.0630---- 162.5------- 148--------- 138.8
0.0640---- 165--------- 150--------- 140.6
0.0650---- 167.5------- 152--------- 142.5
0.0660---- 170--------- 154--------- 144.4
0.0670---- 172.5------- 156--------- 146.3
0.0680---- 175--------- 158--------- 148.1
0.0690---- 177.5------- 160--------- 150.0
0.0700---- 180--------- 162--------- 151.9
0.0710---- 182.5------- 164--------- 153.8
0.0720---- 185--------- 166--------- 155.6
0.0730---- 187.5------- 168--------- 157.5
0.0740---- 190--------- 170--------- 159.4
0.0750---- 192.5------- 172--------- 161.3
0.0760---- 195--------- 174--------- 163.1
0.0770---- 197.5------- 176--------- 165.0
0.0780---- 200--------- 178--------- 166.9
0.0790---- 202.5------- 180--------- 168.8
0.0800---- 205--------- 182--------- 170.6
0.0810---- 207.5------- 184--------- 172.5
0.0820---- 210--------- 186--------- 174.4
0.0830---- 212.5------- 188--------- 176.3
0.0840---- 215--------- 190--------- 178.1
0.0850---- 217.5------- 192--------- 180.0
0.0860---- 220--------- 194--------- 181.9
0.0870---- 222.5------- 196--------- 183.7
0.0880---- 225--------- 198--------- 185.6
0.0890---- 227.5------- 200--------- 187.5

 

smart move sprayedgt, when i read that about the jets i was looking for that same post i found on here and saved a while back. lol, but i guess ill jus start out with what i already had in there jus to get a starting point. a 45 and a 165 and jus go from there. i got called into work when i was about to pull the needle so i have no idea where that is set at. But i do agree with you on the jets... thats crazy they would tell someone to jump from a 155 to a 180., was this a dealer that told you this, or jus a mechanic ?

 

the guy that told me helps with everything from sales to workin on the bikes , he said on his bikes he always starts bout a .180 , dont no what kinda jet he gave me ,but i figured he new more bout it than i did so i tried it , but it didnt work