350x with 250x carb jetting

[darrell43031]

i've search this topic already and havn't found a deffinate answer. i just got the motor today and i'll be starting the conversion next week. just so i can get everything ready i was wondering what main and pilot jets i should be running. and what position on the needle i should be at. i'm only using the 250x carb as a temporary for now until i can save the cash for a 400 carb. and if i helps anybody i will be making my own header and i'm not sure what type of pipe i will be putting on. just a round about guess on what jets will help me just to get in the ballpark. thanks

Darrell

[cals400ex]

i really don't have any clue to tell you where to start. it will take some major tuning. i don't know a lot about the 250x carb, but i can fine tune the 400ex's carbs precisely. i would start high on the jetting. the stock mainjet in a 400ex is a keihin 148. i would probably put the needle clip in the 4th position from the top for starters. by the way, i have a 400ex carb in excellent condition that i may be selling. it is clean with no dirt or any crap on it. it has a throttle cable with it. i can jet it with the desired mainjet, pilot jet, needle clip location, and fuel skrew location if you want it.

[honda250xrider]

i would try the needle 4th clip from the top and start with a 138 main maybe even a 135 main and go from there, and i would probobaly start off with a 40 pilot or a 42 and see what it does

[darrell43031]

thanks guys as soon as i get the motor and stuff fitted into the frame i'll tell you guys how it works out

darrell

oh and i welcome any other ideas or opinions

[darrell43031]

bumpity bump bump

[ATC350X 85]

Heres all the 350x carb specs:

float level: 18.5mm ( .73in )
Pilot screw- 1-3/4 turns out
idle 1400rpm +/- 100 rpm
Main jet 138
pilot jet 45
throttle freeplay 3-8mm
jet needle 3rd groove

hope that helps

[darrell43031]

thanks that does help a little

[zell250x]

im planing on running a 250x carb on a 350x and wondered if you ever got the jetting right for this setup?