I have a 300ex that I’m having some serious difficulty getting dialed in. When I got it back in March it was mostly stock and I really didn’t mess with it much because it was cold. Now that its warm out I’m trying to get it going. It starts with very little effort but when running long enough to release the choke it idles ok for a minute or so then acts like its running lean revs up a couple times idles low then dies. I rode it once and if I go full throttle on it in 5th gear it only goes around 30 maybe. So first the quad has the no lid mod and looks like an aftermarket pipe. So I rejetted it with an FMF kit. I live in Michigan so I jetted it according to michigan elevation, which would have been a 128 jet (I tried every jet between 118 and 128 just to be sure its not a jetting problem) , and #4 on the needle and the air/fuel mixture has been adjusted. Also cleaned the carb while it was out as well. It has a new spark plug and running 93 octane gas now, had 89 octane thought that might be the problem but that is a no go. I’m all out of ideas now. Any help would be greatly appreciated.