I have a 1980 GS850 with individual pod air filters, and a vance & hines megphone exhaust, what size main jets do I need to run? i currently have 115s. 122? 124? Will I also need to replace my needle jets or will the main jets suffice? It's falling on it's face at high RPMs and I am pretty sure I am running pretty lean. I hope main jet upgrade will help solve this.