wont idle for me!!

[sevenhillsbilly]

hey im on the final stretch on my bobber build and i recently had the carbs rebuilt and jetted. i first thought maybe it is just not having the filters on and it is pullin to much air in but thats not it. it will run for about 3 strokes back fire then cut out i have no clue what it is.

help me

 

[bbillington]

what bike is it and what mods? did it run before the carbs were rebuilt/jetted?

 

[Koestum]

Backfiring sounds like a timing issue. I found the most accurate way to check when the points open is with a 12v lightbulb. You can use alligator clips on it... one on the points spring and one on a ground. Then you'll know exactly when the points are opening because the bulb will light up.