GPz1100 carb issue

[Gyesdad]

This is driving me daft!
Can anyone suggest what's to be looked at here? My 1100 uni is on carbs. I've recently replaced the inlet rubbers and cleaned the individual air filters and re oiled them as it wasn't running right and the rubbers were badly cracked. I thought this may cure things but it hasn't.
The bike struggles to idle and rev. Looking at the plugs it's running rich as they're sooty, but if I put the bike on full choke it runs and revs just fine. Correct me please, but doesn't that suggest it's running lean?
As they're CV carbs, should they have a vacuum fuel tap? Mine has a standard 1100uni fuel tap and the vacuum pipe has been blanked off..
As always thanks in advance for your advice!

[z1bman]

first do a compression test + replace the spark plugs. check the diaphragms in the carbs for any splits. the gpz 1100 does not have a vacuum tap. are all the rubber blanking caps fitted to the inlet rubbers

[Gyesdad]

Plugs are new, blanking caps are fitted. I'll look at the diaphragms and do a compression test then come back with the results.
Thanks z1bman.

[steve.w]

is it jetted correctly ??

[lude]

are all the plugs sooty or just 1 ?
was it ever running right ?

[Pigford]

Double check ignition - is there a good +12v at the coils

[Al]

Did you silicone seal the new rubbers onto the head?
Are the carbs clinically clean inside?
Have they been ultrasonically cleaned.
If not have you removed the filters which sit immediately above the float needle jet seats?
You dont need a vacuum tap or vacuum arrangement to make them work.
So long as you have all 4 vacuum take-offs' on the bodies blanked off and there is a prime position on the tap which delivers full flow you'll be OK.
Is the valve timing more or less correct.
Cams can move easily within the hyvo chain and mess stuff up very easily.
If the timing is a little retarded that will supress idle vacuum and lead to poor idling and poor pickup off idle.
You mention that all plugs are sooty. This doesn't necessarily mean that it is running rich. It may be a severe missfire that leads to blackening of the plugs. It could still be lean. If it is then use of the choke will correct it temporarily.

Will be interested to see the compression figures as well.

AL

[Gyesdad]

Gents, thanks for your input!
There's a lot more here to check and think about than I thought would be the case! I'm working away until next Monday, I'll get stuck in and answer your questions when I get back.