KZ750H Starts full choke only, no choke warmed up

So I am looking into why my bike only starts on full choke.

When I start it on full choke it will idle at 1000 for about 5-10 Seconds then the idle with quickly jump up to about 4000 and I cut it to about half choke until the engine is warm.

after it warms up the idle will fluctuate as much as 700 RPMs.

I know the carb need to be synced.

I tried adjusting all the idle screws( I think, they were on top front and centered). . they were backed out pretty far so I turned them all the way in and backed them out 1 1/2 turns and it runs exactly the same. I haven't chopped the plugs since I made the adjustment a few days ago though. last time I checked them they looked good.

The pervious owner drilled holes in the baffles so it may need a rejet.

the carb had some sediment in the bowls when I looked at them but no varnish or gunk otherwise. I blew them out with compressed air.

no problems with acceleration or random dying.

it is slow to return to idle if I drive with the choke on to maintain idle. sometimes the idle will jump up if I let off the clutch and gas when in the 3500 RPM+ range(with choke on to maintain idle).

I let the bike warm up enough to let the choke drop at least half way before I drive and drop it at every stop until it's off.

Havent flushed the tank and it is quite dirty however the petcock fuel filter is in great shape, Should i install an inline filter anyway? ( I will flush the tank tomorrow)

any thoughts, suggestions?

and for those of you that remember my last post (I was intermittently loosing power while accelerating) the problem went away one day and has not returned. I don't know what the issue was, but it resolved itself for now.

Bonus question, what color should I paint my bike, It's already prime red!

The odd part about this is that with the choke on the bike exhibits symptoms of running lean. however once it warms up it has no symptoms of running lean.

KZ engines are generally cold blooded so using choke to start a cold KZ is normal, and after a couple seconds the revs will jump, so you must reduce the choke; riding with the choke on will result in high revs as you describe. All that is normal. The idle fluctuation with choke off sounds like a vacuum leak. Check carb holders for leaks (let us know if you need instructions) and make sure vacuum caps are on carb holders. Ed

Like 650ed said it sounds like a vacuum leak. An in-line fuel filter should be run, but make sure it will flow under the gravity feed system. Regular pressure system filters can starve the carbs for fuel. Having all of the Idle Mixture screws at 1-1/2 turns out from lightly seated is good for a first setting to get it started, but more than likely will need further adjustment. Get it warmed up real good and adjust them then. In = Lean, Out = rich, so get them so each cylinder drops as you turn them in. Then Idles strong after turning back out, around another 1/2- 3/4 turns. Vacuum sync so each is drawing the same amount is going to make the bike run a lot better at Idle and low speed throttle. There are several Manometers on the market, or you can make one.
www.kzrider.com/filebase/doc_download/215-simplevacsynctool

How did you get to the air screw?? I can not seem to get my plugs out.

Air screws are up on the side of the carbs. Here's where they are on VM24SS carbs:

I had to take my Tank off and prop it to the side to get to the air screws.

I will Check for vacuum leaks this weekend. and find a fuel filter

I do have a vacuum leak!!!