If only I would have seen this earlier. I had that same issue on my piped viper years ago. I also had EGT gauges on my so I could see when the fire went out. Mine was good for either idle or WFO but if you midranged it, it would puke out the MAG cylinder. I had previously put a XCR800 38mm rack on it, and at some point I decided to put the stock carbs back on. I had cannibalized my stock rack for screws and clips for the 38s and didn't want to get in that habit of swapping parts back and forth on the carbs, so I picked up a complete set for cheap on the ebay and put my jetting in it. Well the first decent trip out is when this happened with the fire going out and I was not in a position to tear into things. I ended up swapping all of the parts I needed from the new stock rack to my original stock rack when I got home and had no problems, but when you talk about float levels, the MAG float was set lower then the other two. I figured that was the problem, but just ended up putting the original rack of and never had a problem after that. I have since gone back to my XCR rack just because the tuning is much more predictable and I get better mileage.