XS850 engine coughing problem

[srq68]

I have a glitch with what I think is a carburetion problem that only happens when the engine it hot, like after a highway run, never cold. It goes like this:
When I get to a stoplight or a toll plaza when the engine is warm, the idle is nice and steady at 1100 rmps, but once in a while, the engine seems to "cough" for a split second and the rpms drop tremendously to the point where the engine dies somethimes. If I blip the throttle when it happens, I get the rpms back and the iddle comes back.
Again, it only happens at hot temps. I figure it has something to do with the carbs. I rebuilt them, put in-line gas filters, adjusted the pilot screws and sync'ed them just 2 weeks ago.
Any advice would be great as usual.
Thanks

[xssiveone]

Did it do this BEFORE you did the work on the carbs, or after? I'm wondering if the routing of your fuel lines with the added filters are causing vapour lock and shutting off your fuel flow.

[srq68]

The fuel lines and carb rebuilts were done during the restoration. The lines are kept to their shortest and no kinks.
There are 2 lines feeding the 3 carbs, could vapor lock in one line be enough to cause that problem?
I don't remember for sure but I don't think this happened until I was riding in the hot summer days.

I'll keep an eye on that, maybe with the petcocks on "PRI" the problem would go away?

[ratbyk]

Carbs-Again

My guess would be that one of your needle and seats is not sealing off every time and one one carb is starting to flood. No problem at higher engine speeds, you are using fuel fast enough to use up the excess but at idle, particularly when warm that cylinder cannot use all it is receiving.
Ken/Sooke