GSX400F hanging idle issues, losing the plot

[ukjules]

I have had this same problem on at least 2 of my bikes.
I to be honest can never put my finger on one thing that fixed it but i regiment-ally go through all tuning again and again.

I think i am useless at using my vacuum guages at least on a engine not run for years and only when i bench sync the carbs sync did i start
to get all the parts working right.
re check timing, valve clearances, plugs, ht leads, coils, mixture, airleaks around carbs

think you are getting close - hows the carb sync ?

[Kayak23]

well I synced the carbs yesterday with my gauge set via eBay and got them all close to each other.

I think the thing for me is knowing what order to check things. Check something, rule that out/fix that and then move onto the next.

At the moment because I'm rusty and not so experienced I'm probably chasing my tail a bit.

Having said that though, my strip and rebuild of the carbs, bench sync and general tinkering have defo improved things but it looks as if I'm going to have to take things a bit further if I want to get it all working as best as it can.

I think that's going to involve taking the head off and seating the valves perhaps.

Also, my last bike, some 16 years ago was a lovely 1974 Z900, and I have to remind myself that this is a little 400 and will never pull quite so well...

[ukjules]

I at this point always go over what's done.
Doesn't hurt and doesn't take long. Need to be exact.

Timing
Plugs
Mixture
( You said valve clearances all ok )?

How are these and how are the plugs after a run
with them all set ?

P.s I agree with everyone else but trying to restart
and check all basics ...