• Ok might be a stupid question but does the type of carb determine what size jet...

    Ok might be a stupid question but does the type of carb determine what size jet or is sizing standard to each carb very important question

    11 comments
    • I'd be inclined to start with the 180 because if you're guessing a bit you'll want to start rich rather than lean.

    • Ok sounds good thanks man

    • Yea might be a little to rich

    • I can't believe that you can even buy a 350. Might as will unscrew the just and just chuck it away. It'd have to be a methanol jet for a 125. My old YZ125K's got a 280 main in a 34mm carb but that comes back to sort of the same thing as I said about bigger carbs needing bigger jets cause of less vacuum. 125's also need bigger jets because of less vacuum than the 250's.

    • It came with it i didn't even realize it

    • It came with two jets a 370 and 350 I didn't even check it the kid before said it ran like shit and I just did a complete motor swap the only thing that stayed was the carb

    • Swapped motor cause the 93 was jbwelded

    • I reckon someone's been running it on Methanol. That's the only explanation for a jet that big. you want to check your pilot jet too. How big is it ?

    • Have to check it's pooring right now and I'm with my son I'll pull them both in a little

    • I'm just looking at the Haynes manual now for jet sizing - according to this, the main jet size is 170. However the YZ125 for this year is 350 (main jet) maybe a mix up previously? Just thought I'd let you know as I was looking.

    • Thank u