Discussion Starter · #1 ·
I put the performance kit from HMF on my 500S (slip-on, 170 main j., 2 1/2 turns out on a/f screw. Last night me and my wife were riding around on my parents place and she said that about 2 or 3 times when I changed gears she saw a small puff of grey smoke come out the exhaust. She said it was just a very small amount and if she wasn't looking right at the exhaust she probably wouldn't have noticed. My question is could this be a little unburnt fuel or could it be too lean? I believe it was only doing it at higher rpm and when I swapped gears. Not worried about it too much just wondering. Thanks everybody!