98 Fzs6 reverting from 2/3 cyclinders to 4 constantly.

[riz]

The icing used to happen to me after 10-15 miles of a mixture to speed's, but i noticed it in the slower speed areas, and then above 7-8k rpm it seemed to clear (or was that 4-5k?, cant remember), it also happened once on the m4 comming back from the ace later at night after 30 mins or so of pretty constant throttle. Icing isnt just about temp. its also about moisture in the air.
If you hadn't mentioned the fuel pump relay i would have suggested coil's.
When it happens if you give it WOT does it clear at any point?

[KyleBeeson]

Kind of, but its unreliable there most of the time are no beans to give it

[darrsi]

It's extremely unlikely to be carb icing, it's too warm now.

[richfzs]

carb icing? as others have said, no chance.

check the routing of the breather pipes, its easy to kink them on the early bikes, creates a low pressure in the tank, and try as it will, the pump cant get the fuel down to the carbs....

[KyleBeeson]

I doubt the fuel lines have been changed, so a 15 year old bike I'm sure the lines would need changing soon or more importantly now

[Dead Eye]

Can't see a need to change them unless they are quite literally falling apart - certainly a cleaning out might be a good step in case there is a build-up of crap

[KyleBeeson]

Breather pipes the other 2 pipes attached to tank?

[Dead Eye]

The earlier bikes (which should be yours if your profile is right - 98/99) have three pipes coming from the tank - two small ones are breather pipes and the larger is the fuel supply to the fuel pump / filter (I forget which comes first )

If the breather pipes become kinked then it creates a vacuum in the tank which eventually will prevent fuel from being pumped out. Does the tank hiss when you open it to put fuel in? The fuel pipes could be kinked or have a build up of crap in them from years of use. Just follow the larger one from the fuel tank to the pump & filter then on to carbs

[KyleBeeson]

Filled up last night lol, so fuel has gone everywhere and basically they were bent and cracked abit, so I've cut the crap bit of Line off and linked up fresh hose, and went to put the tank down and it went to bend it again -.- so just about sorted it out.. I doubt for some reason it's this, just seems something more. Next will be a fuel filter change and if that doesn't solve it gonna get all the hoses changed and carbs balanced etc I think