My bad, main is 390. And yes it is the mikuni tmx with square slide. I have the iridium plug from ngk #8 , last time i checked plug was on the black side. After that i put the needle clip to 2nd from top and screw 1,6 out. Now i need to check again, but being my first enduro husqvarna i am curious of they are al sluggish @ low rpms? My previous motocross bikes, kx250/ rm250 did not hesitate when opening the throttle. Now i work the clutch in slippery corners to avoid the hit, normally wit a 250 this is not neccessary.