97 katana idle issue

[Jreid843]

Hi, I have a 97 katana that has trouble idling. When I first got the bike I had to crank it with choke all the way on. After running some 44k fuel treatment in it I can now crank it without the choke but I have to give it some throttle to keep it running. I figured the carbs needed to be cleaned so I took the carbs off and started to clean them but when I took the bottom bowl off the carbs look brand new. Some one had to recently clean them. Now I was wondering what else could cause an idle issue. The bike runs flawlessly while riding. No backfire, nor any hesitation after warmed up. I got the bike from someone who was not mechanically inclined although they said they were. I can tell whoever worked on it last sucked as a mechanic. I had oversize replacement bolts, stripped screws, missing screws. You name it I saw it. Bottom line... If the carbs are not dirty what can cause an idle issue? A few other things that might help. I noticed while bike running if the choke is 50% or less open it doesnt make a difference til the bike is fully warmed. When coming to a stop light after bike is warmed up it idles at about 2500 rpms for 5-10 seconds then drops to less then a grand and dies. If I turn the idler screw it pretty much doesnt make a difference. Any help would be lovely

[Tempted]

Dude, that's what the choke is for.

[Jreid843]

Dude, that's what the choke is for.

After its fully warmed up it still will not idle. If I sit at a red light it idles at 2500 then dies after ten seconds

[Maverick.Marq]

Carbs need to be cleaned; sync'd; and then idle adjusted propertly when warm

[Tempted]

After its fully warmed up it still will not idle. If I sit at a red light it idles at 2500 then dies after ten seconds

HThe bike runs flawlessly while riding. No backfire, nor any hesitation after warmed up.

But chances are it needs synced.

[Jreid843]

Carbs need to be cleaned; sync'd; and then idle adjusted propertly when warm

Thanks. Although they appeared to be clean already I went on and cleaned them anyway. Will look more into getting them sync next.

Also while carbs were apart I noticed the passages for the choke seemed a bit off. I would think when the choke is off nothing should be able to flow thru the passage, but I noticed while choke is off 2 are fully blocked off and other 2 cleaner was able to flow through them. Is this normal?