Try unplugging your TPS, the plug is a hassle to get to. It is located atop the engine case beneath the carbs. But it's easy to put back together in the future, should you decide to. Eliminating the AI is just a plain good idea too, it serves no good purpose except to heat stain your headers or cause carbide precipitation, if you want the correct technical term. Both of these methods have reduced popping and backfires for many of us. One thing I question though, your dealer says your jets are correct, if so, can they actually tell you offhand, what size of jets are installed in your carbs without guessing? If you do change out the jets, pull your carbs, find the best fitting Phillips screwdriver you can for those (easy to bugger) soft alloy screws, remove them and replace with Allen cap screws (source from FastEddy), then you can do a jet change without having to pull them again the next time. The good news is that once you have them dialed in, your done, unless you change the in or out flow of your motor.
