zaphoid18
XS400 Enthusiast
I'm pulling my hair out on this one guys. 
when I close the throttle coming to a stop the rpm's plummet and if I don't keep the throttle cracked open the engine will die while stopped.
consistently idles around 600-700 rpm at idle. The idle screw does nothing to raise the idle even when completely screwed in.
it will start but its somewhat difficult. the choke doesn't really do anything on starting, half choke will raise rpm when idling about 300 rpm and full choke will kill the engine.
otherwise the mid and top range performance are great and the engine is super strong
The specs:
1979 xs400 with 1981 carbs (tintops)
stock airfilter and airbox
aftermarket shorty reverse megaphone pipes
mains 140
pilots - worked my way back from 47.5 to 45 to 42.5 with no improvement
idle mix screws set to approx 3 turns out
floats are rubber set to approx 22.5
new points, coils and condenser
new carb mounting boots
carbs have been synced multiple times
carbs have been cleaned cleaned boiled and cleaned
recently found a small air leak on inner throttle shaft seal causing intermittent hanging idle but i don't think that's related since after i pull the rpm down through the hanging range (3500-4000 rpm) if i don't open the throttle some the rpm goes low and dies.
please help if you can i'm not sure where to go from here
Thanks a lot
when I close the throttle coming to a stop the rpm's plummet and if I don't keep the throttle cracked open the engine will die while stopped.
consistently idles around 600-700 rpm at idle. The idle screw does nothing to raise the idle even when completely screwed in.
it will start but its somewhat difficult. the choke doesn't really do anything on starting, half choke will raise rpm when idling about 300 rpm and full choke will kill the engine.
otherwise the mid and top range performance are great and the engine is super strong
The specs:
1979 xs400 with 1981 carbs (tintops)
stock airfilter and airbox
aftermarket shorty reverse megaphone pipes
mains 140
pilots - worked my way back from 47.5 to 45 to 42.5 with no improvement
idle mix screws set to approx 3 turns out
floats are rubber set to approx 22.5
new points, coils and condenser
new carb mounting boots
carbs have been synced multiple times
carbs have been cleaned cleaned boiled and cleaned
recently found a small air leak on inner throttle shaft seal causing intermittent hanging idle but i don't think that's related since after i pull the rpm down through the hanging range (3500-4000 rpm) if i don't open the throttle some the rpm goes low and dies.
please help if you can i'm not sure where to go from here
Thanks a lot
