Ok here goes. 92 Banshee. Stock with Toomeys, K&N, Jets at 270, runs absolutely perfect.8 years later, top end goes. Went with one step up on the piston, recreational porting and polishing. Yamaha dealer said that jetting was too small, go with a 300. Results are mid to full thottle popping and hesitation. Taking it to the dealer was my first mistake. Any serious suggestions?