Legend 900tt Poor Cold Starting

Hello, I bought this 1999 bike with 7200 miles on it last year, it had dealer 1 month warranty so I did some miles before winter and all seemed ok. As it was winter I couldn't help stripping off the panels and going deeper as I found it was difficult to start when cold, she turns over fine but getting the sweet spot on the choke position was a game, it turns over, catches then instantly fails, touch the throttle and it dies instantly. The only way I win is if I keep turning over, it catches then fails, then try again and it catches longer each time, after about 10 goeas getting longer each time an ease of the throttle gets it and you can get the revs up, it sounds like its on 2 then 3, as soon as it warms (within seconds) its running ok and will tick over, granted with a bit of choke until proper warm, ride and pulls no problem. Leave it for hours and it takes a couple of goes to start, leave it for days and its back to the beginning.
It had been stood for years before I got it, hence the low miles so; I pulled the carbs and cleaned them, checked all jets etc, idle jets were 3.5 turns or so, checking forums it appeared 2 was stock so that's what I put them to. New plugs,new air filter as it fell apart (pipercross) found the coolant to be Tomato soup so flushed it all out and re-filled with Putolene. Put her all back together (what a pig they carbs are) and it is now starting exactly the same as before!
Haven't balanced the carbs (I have been contemplating cost of having them set by someone with buying gauges) but I did sync them.
All valid ideas gratefully received

 

Thanks for the response, no aftermarket exhaust, its all stock. Interesting you say leak, I thought I could hear a 'fluff' at the carbs but difficult to say. I have the tank jacked up, I have checked all rubbers and clips and all appear in place, I checked the rubbers before I fitted them.
Why would an air leak let it run warm but not cold?

 

Hi, thanks to Sprinters nudge I checked out testing for air leaks on youtube, couldn't be simpler, get her idling and spray the test area with either jump start or propane gas from the blow torch, any leak will allow additional fuel in and the engine revs. To my amazement LH carb to head rubber which is easiest to view and sat prefect was the worst culprit, all caused the engine to rev up with just a short burst. Set of new seals and clips are £26 from Sprint manufacturing on Fleabay so no buggering about, replace.
I will of course advise on progress as it occurs.
I have to say the dealer said they would want to go through it proper as it had been stood for years, utter bolox, I found all grease nipples dry, the coolant needed swapping, the air filter was rotten. As usual, new oil and filter (if I am lucky, haven't checked yet) new plugs and rubber stamp the book. I was surprised they had done the middle plug, same old same old.

 

Whats the opinion on carb balancing, if you have set all up stock does it run pretty good until vac gauges finish it off, anyone seen astonishing results?
Anyone set it up with 2 gauge set?

 

Hi, owned from new! Respect.
My mate sold his as he is ill again and its just too big for him now, it sold in a day at full asking.
So interested in your response, i was convinced the issue is now electrical as i got a two carb balancer (piece of piss to do, centre and right, then swap left to right and back, what a difference) but it is a lot better, but not 100% i pulled out on the road too soo after starting, opened her up, she died and dipped then lifted her skirt and went mad.
I still might swap lh and Rh plug, then lead then coil. Check the plug colours then shut up and ride.
My buddy is off road at the minute, Honda Adventurer 12k and his 4th gear gone, 5 weeks waiting for parts and £1400 bill after arguing, he listed an issue on service 1 +2 now they say driver error. I have not ever found a good honest main dealer. My new Peugeot car is serviced by the garage i know.