Yamaha dt 5o mx 1991 advice

[Gary fullman]

Ive a 1991 dt 50 ive ungoven the exhaust .put 60cc kit on it but dont seem to made any diffrence .was thinking of re jetting carb but dont know what size to order ive ordered another exhaust .any good advice well come .would skimmed head help ? 

[wild foamy]

rejet is nescessary, #88, raise needle one slot