hi, i have a 2005 yamaha dt 50 sm and im putting a 90cc big bore kit into it and i dont know what size of jets i need ,the jets in it are size 76 ,i have rung yamaha its self and they dont know , any help would be helpful, thanks

An intoduction would be nice in the New Members forum.

i have read up on a website that you will need to up jet to about 10-15% higher than the normal jet size, but its just trial and error with the jets, keep changing them untill it runs sweet

Ok thanks very much!