Premix?? If you do a search on premix you will probably come up with tons of info. seems everyone has a different opinion on this, here's my experience. We have owned the KDX for 4 years now, the previuos owner had done all the mods that are on the bike to this day. ON our first ride (premix 32:1) it smoked alot and covered the rear fender with oil! Thats when I started reading the threads about premix, I tried different ratios up to 50:1, I tried different oils, and repacking the silencer but nothing changed untill I started changing jets. By this time I had settled on a ratio of 40:1, the previous owner had a 155 main, with the needle in clip #3, I changed to clip #2 and worked down to a 150 main, this made improvements in the amount of smoke and the amount of oil on the silencer/fender commonly known as drool or spooge. Then I went to a 145 main and low and behold no more spooge at all, zip zero nada! I intend to go back to the manufactures recommendation of 32:1, but have been at 36:1 for the last year. I must come clean, I never ran a 148 main, I was worried you might fry your motor, the 4 times I've been to Utah (3 to Moab,1 White Wash) we rode in lots of sand, I've always heard you should run richer in the sand. As far as ratios go I think I'll stick to the manufactures specs, for me that means 32:1 for the KDX & YZ, 50:1 for the KTM. :coocoo: