Something's definatly up with your setup. I got your email, but didn't read this post before I replied. You have the potential to run mid thirties with that setup. Mine is set up with the stock cylinder, minus the ase and head gasket to increase compression, a bosch platinum spark plug, a stock 12mm carb, a 70 jet, a high flow air filter custom built, and the same techno Boss exhaust. I'm running 14-40 gearing, and I have no problem hitting between 30-33 on the flat. Granted, seeing as I'm a heavy guy (250 lbs on a good day) it takes a few moments to get up to speed, but it doesn't take forever, and I CANT hold mine back by just holding the seat with the throttle open. Something is screwy with your settings. The smaller jets will solve the richness problems, but if you want to add power you should probably come up with a better air filter. Autozone sells breathers for car transmissions that can be adapted for the purpose nicely.