best size jet to start with

[blaster003]

i have a 2003 yamaha blaster with stock mikuni carb, boyesen reeds, fmf fatty with powercore2 and i have the lid removed with kandn filter, outerwears cover with stock airbox i currently have a 32.5 pilot jet and 260 with stock needle but my plug is a light/dark gray which is lean what jet size do i need to go up to i would like to start at a close size i have 260-290 main jets now i really wanted to try to jet the bike close to perfect without doing a plug chop now beacause i am rebuilding the topend this week and i dont want to run it wide open now for a plug chop. my elevation is 400 to 1200 because i ride differnt areas . thanks.

 

[Herpderplol]

i think 280 would be where you are sitting. almost 1000 feet in elevation change adds a jet size too.
so try 280 at the lower part, and if it seems good, try 290 if not too rich

 

[Blaaster]

What he says /\ /\

 

[blasterkid1998]

i ran almost that exact same setup on a blaster i sold about 1 month ago. It ran a tad rich with a 280. and im at about 800 feet of elevation.

 

[MercMenace]

At 0 - 2000 ft of elevation you should not see a need to change jetting. In my experience with major altitude changes, every 2000 ft higher in altitude requires you to go DOWN 1 Jet size. I would start with a 280 at home. if you go higher in altitude it will only run richer.