1978 XS400 2E
Mods:
MikesXS pods/Stock airbox
Emgo shorty mufflers
Carbs:
26mm float height (verified correct with external clear tube)
150 mains
47.5 pilots with stock airbox/50 pilots with MikesXS pods
Maintenance performed within last 2 weeks:
Timing set
Points replaced
Condenser replaced
Carbs synched
All carb internals replaced with new except diaphragms
Symptoms:
The bike runs beautifully; I ride it daily and even did a 400+ mile trip the other day through the mountains. I am still struggling to keep a reliable low idle, however. It has been very hot this summer and I do not remember having any problems earlier in the season.
The problem occurs with the stock air box and with MikesXS pod filters.
She idles best at 1,200 to 1,500 rpms, but every 10 - 20 seconds I can hear the engine miss a beat. Occasionally she will die at idle, but not often. She has only ever died when at full operating temperature while sitting at a red light. Often I can hear the idle start to get low and save her from dying by applying a tiny amount of throttle.
With all I have replaced and done should I be looking at the coils/wires/plug caps? I am still running the originals (34+ years old) and thinking I might have a weak spark.
Thoughts?
I may just replace this entire section of the ignition system for the sake of reliability. Worst case scenario it knocks a potential cause off the list.
Mods:
MikesXS pods/Stock airbox
Emgo shorty mufflers
Carbs:
26mm float height (verified correct with external clear tube)
150 mains
47.5 pilots with stock airbox/50 pilots with MikesXS pods
Maintenance performed within last 2 weeks:
Timing set
Points replaced
Condenser replaced
Carbs synched
All carb internals replaced with new except diaphragms
Symptoms:
The bike runs beautifully; I ride it daily and even did a 400+ mile trip the other day through the mountains. I am still struggling to keep a reliable low idle, however. It has been very hot this summer and I do not remember having any problems earlier in the season.
The problem occurs with the stock air box and with MikesXS pod filters.
She idles best at 1,200 to 1,500 rpms, but every 10 - 20 seconds I can hear the engine miss a beat. Occasionally she will die at idle, but not often. She has only ever died when at full operating temperature while sitting at a red light. Often I can hear the idle start to get low and save her from dying by applying a tiny amount of throttle.
With all I have replaced and done should I be looking at the coils/wires/plug caps? I am still running the originals (34+ years old) and thinking I might have a weak spark.
Thoughts?
I may just replace this entire section of the ignition system for the sake of reliability. Worst case scenario it knocks a potential cause off the list.