250r jetting

[falconkid417]

hey i have a 87 trx250r it has a fmf fatty head powercore pipe v force reeds and i am boring it to 20 over and i need to know what size main jet and poilet jet i need?

[89rebel]

1-2 mainjet sizes more likely, your air screw will change from day 2 day. I had the same setup on my 86,.060 over and had 42 sj, middle clip pos and 158 main.