Won't start two days in a row, please help!

Ok so I pulled the carbs re-did the bench sync, and reset the pilot screws to 2 1/2 turns, it fired right up and sounded smooth so I went for a ride and all was good however it did seem to take a while longer to warm up so i could turn the choke off all the way, once the choke was off I adjusted the idle to spec and went for another ride, lots of power, no sputtering, no stalling and I'm lovin life.... Yesterday morning I start her up for my ride to work, she runs for 30 seconds and dies?? then won't restart, this morning the excact same thing and I'm cageing it to work again!!! I haven't had any time to look at anything yet but I'm not sure where to start, any ideas???... other than listing it in craigs list!!
Shaun

 

My guess would be that something is out of place in the carbs, seeing as that was the last thing done to it. Take them off, take them apart again, make sure the floats are spec'd out. Make sure they're all spec'd out, make sure everything is still clean.

If you go through them again, I would bet you'll find your problem once you open them up. Could just be something simple.

 

plugs and oil change
I dont see plugs in your sig as being done.

plugs are picky little things on bikes.

 

Make that three days, but it seems to be a cold problem be cause when I got home it fired up and ran fine??!! the problem is that it not that cold in the morning, this morning it fired right up ran for about ten seconds but no amount of throttle or choke could keep in going, it died and then wouldn't start again.
Shaun

 

Try putting the petcock onto prime then starting.

I am suspicious my bike has a similar fault and I don't think the fuel is flowing freely on "On". Mine would die after 400 yards or so.

Prime fixed it for me - yes, I know I have to fix it properly!!

 

are you using a inline fuel filter? if so is it full of crap from the tank? Is the vacuum line on? Any cracks in it?

 

petcock works perfect I just rebuilt it, new hoses, no filter, gas tank relined over the winter and the inside screen is clean!! I tried it on prime this morning just to be sure but it made no differance, but this problem only started since I reset the carbs to spec and re-synced them, when it runs it runs better than ever but won't start when it's cool in the morning!! starts fine in the afternoon when it's warmer? I am going to pull the plugs when I get home but thay are fairly new and should be fine.

Shaun

 

how humid is it where you live? what is the temp at night?

 

How's your battery charge?

My 400 was cranky the other day.... been happy after a quick charging......

Our over night temps are dipping close to freezing last coupke of days....
Colder morning like fully charged batteries