Two Stroke Motocross

Two Stroke Motocross Forum => Technical => Topic started by: helfrick15205 on February 24, 2010, 03:53:23 PM

Title: 86 yz 250 carb
Post by: helfrick15205 on February 24, 2010, 03:53:23 PM

i just put a new vm 38mm carb on my 86 yz 250. every thing inside is 1 step leaner than the stock carb (main, needle, ect.). it has a lever choke on it and i dont know what position the lever has to be in for the choke to be on. i started it with the lever down which i think is the choke on and it ran fine and every time i pulled it up it bogged and wanted to die. am i correct in assuming that it is running to lean? i have the old carb and can change out every thing except the slide and needle.

Title: Re: 86 yz 250 carb
Post by: evo550 on February 25, 2010, 03:44:07 AM

Yep,
sounds lean to me.

Title: Re: 86 yz 250 carb
Post by: mxaniac on February 25, 2010, 09:05:53 AM

Lever down is choke on for the VM.  Bog without cleanout is lean, bogging and then cleaning out is rich.  I would look for air leaks too, some bikes from the 80s needed to be jet several sizes leaner than stock.