Okay, so a bit of back ground on this before i start. I have rebuilt this TX650 motor, inside and out with .25 over pistons, new wiring with pamco and brand new VM34's mikuni carbs. Now, i've had it running a few times and i immediatly noticed that the left exhaust pipe is hotter than the right. To the point that its tarnished the new stainless on the left. So i thought it might have been a lean mixture and pulled the carbs down, even though they're brand new i blew out all the jets and passages. Reassembled with these settings, Air mix screw 1 turn out pilot -25 main - 220 needle - 6F9 middle clip position Needle jet - 159 0-2 I started it again and used a thermal pointer, the left is 210 degrees where as the right was around 150-160. I've double checked valve clearances to be sure, gone back to BPR6ES plugs as the iridiums died on me and ive never had much luck with them anyway. To top all this off, when i was trouble shooting the bike wouldn't start anymore I have spark, plenty of fuel and used another set of plugs to no avail. The only think i can think of is the pamco has somehow played up and the ignition timing isnt right? Anyway, any help is appreciated.