Tx4wler- I am at around 700' and I recently installed a Supertrapp exhaust. I also have the K&N/outerwear and DJ kit. Before the exhaust, I was running the 144 and the needle on the 2nd notch. After running it an hour or so with the exhaust, the plug looked lean so I went with the 148 and left the needle on the 2nd notch. Just idling and playing with it in the garage, it spits a little black smoke but after actually riding for an hour or so, it still looks a little lean. I will probably end up with the 150 or the stock 152 later and see how it goes. I really haven't ridden it enough to tell what is going on and how much, if any, the exhaust helped. I am going to Little Sahara, Utah next week and it is around 3000' there so I may have to back up to the 144 or smaller. Before the exhaust, I had tried a 160 at 3000' and it was way to much until I took the air cleaner lid off. It at least ran good enough that weekend until I could get back home. I recently read a post of someone running a 158 so there may be some room to go on up with the size. It's just a pain to change it. Plus, I live with Murphy's Law and just know I will drop something in the dirt trying to change it in the sand. Did you experiment with the different needle setting? Seems like the fourth would be pretty rich at low speeds.