Engine flooding

Hi all,
new to this forum, so if I'm doing anything wrong feel free to correct me. I'm in the UK and have purchased a kz1000g Z1 classic. 
The question i have is that I am having trouble getting it started. When I start it from cold it will fire up, but after about several seconds it stops and then it just cranks over with out starting. Checked plugs, good spark. Checked injectors, fuel coming out, however the plugs are black and wet, so this is telling me that it is flooding. What could be causing this.
I am considering doing a carb change, so what would be a good set of carbs, and what do I need to remove remove and play around with to do this conversion.
Any help would be greatfull, as I am pulling what hair I have left out.

Welcome from Leicestershire. The below link may help you

1980 z1 classic fouling plugs - KZRider Forum - KZRider, KZ, Z1 & Z Motorcycle Enthusiast's Forum

Welcome from Brands Hatch, Kent. 
Don't know anything about the injected systems but presumably they have an enricher system of some kind? With carbed models full choke is only used on initial firing then the choke is feathered back to the lowest point to maintain running. Then decreased further as it warms. 
Is that the principal for the injected models? or is it all done in an ecu? 

It's an ECU that determines injector duty cycle based on a signal from a temp sensor (the mod I detailed in the attached link simply provides a manual "cold start" setting") as a cost effective option to an expensive ECU repair

Single clothes peg in summer and double clothes peg in winter was always foolproof  on my 69 mini cooper. Some progress is a retrograde step 🤣
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Warren3200gt wrote:

Single clothes peg in summer and double clothes peg in winter was always foolproof  on my 69 mini cooper. Some progress is a retrograde step 🤣
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That was great until the engine earth strap broke, then the choke cable would glow red during starting and set your pegs on fire 

Hadn't invented health n safety in the 70's Guy. Back when men where men and smelt of Brut, girls didn't have trout pouts and a bloke with a top bun would got a good kicking. 

Hi there, there is a cold start on the throttle bodies, it's not controlled from the ecu. 

kznutter wrote:

Hi there, there is a cold start on the throttle bodies, it's not controlled from the ecu. 

Correct, however the fuelling is still controlled by the ECU as far as I am aware determined by a temp sensor (hence the link I posted)

Wookie58,
That's right, the fueling is from what you said, but it does seem to be functioning but to much. I'm beginning to think that it may be the fuel pressure regulator, so a few tests need to be done on that, and if that is the case, trying to find one. This bike has done just under 5000miles, so its been sitting around for a long time, so the diaphram could be suspect.

kznutter wrote:

Wookie58,
That's right, the fueling is from what you said, but it does seem to be functioning but to much. I'm beginning to think that it may be the fuel pressure regulator, so a few tests need to be done on that, and if that is the case, trying to find one. This bike has done just under 5000miles, so its been sitting around for a long time, so the diaphram could be suspect.

I would suggest also checking the resistance of the temp sensor (if it thinks it's colder than it actually is it will over fuel) Don't forget these sensors are NTC (negative temperature coefficient) so the resistance "decreases" as they heat up

Good call, i will do that as well. Cheers.