Speedfight 2 problem help would be much appreciated thank you.

Hi i have a peugeot speedfight 2 installed with a 70cc kit, 8.5g roller weights, stage 6 clutch springs (2k), a sports exhaust, 50cc carb and a K&N free flow air filter i really need help with finding the right size jet just lately i put an 85 jet in but it seems to bog at times like it will do it on accelerating sometimes or it will do it around full throttle. just lately my bike has started to make a rattling noise i'm not too sure on what it is and whether it is to do with the fact my jet is to small.. My bike doesn't idle very well either it cuts out so when i pull up to traffic lights i have to have a little throttle to keep it running i am wanting to put my standard air box on as it's cold winter weather and the open air filter won't be doing my bike any favours can anyone help please?!