High Idle then low idle

[katlover2012]

hello,

I have a 93 katana 600

The problem im having is that when the bike is cold no choke this is what happens:
idles: 3000rpm for ~15-30sec
then it idles at 1500RPM for 5sec then it compeltely dies.
if i blip the throttle right before it dies then it will shoot up to 3000rpm and then repeat the process

when bike is warm and no choke:
idles: 3000rpm for ~15-30sec
then it idles at 1500RPM steady
if i blip the throttle, then it will shoot up to 3000rpm and then repeat the process
also when riding and when i get to a stop the bike idle at 3000RPM then it goes down to 1500RPM after about 30 secs

if anyone could tell me whats wrong and where to start that would be great
If there a thread on this, then can someone show me a link to it

BIKE INFO:
valve clearances checked and are within range
I have read carbs 101 and when I cleaned the carbs, it feels like it helps but no help when warmed then after riding awhile it goes back to the process descirbed above.
I have the A/F at 1.875 turns out
I haven't checked thoroughly for vacuum leaks
I have synchronized the carbs but no affect to this problem.
I have a 4into1 yoshimuri and a K&N filter

Thanks
Frank

[Kreylyn]

hello,

I have a 93 katana 600

The problem im having is that when the bike is cold no choke this is what happens:
idles: 3000rpm for ~15-30sec
then it idles at 1500RPM for 5sec then it compeltely dies.
if i blip the throttle right before it dies then it will shoot up to 3000rpm and then repeat the process

when bike is warm and no choke:
idles: 3000rpm for ~15-30sec
then it idles at 1500RPM steady
if i blip the throttle, then it will shoot up to 3000rpm and then repeat the process
also when riding and when i get to a stop the bike idle at 3000RPM then it goes down to 1500RPM after about 30 secs

if anyone could tell me whats wrong and where to start that would be great
If there a thread on this, then can someone show me a link to it

BIKE INFO:
valve clearances checked and are within range
I have read carbs 101 and when I cleaned the carbs, it feels like it helps but no help when warmed then after riding awhile it goes back to the process descirbed above.
I have the A/F at 1.875 turns out
I haven't checked thoroughly for vacuum leaks
I have synchronized the carbs but no affect to this problem.
I have a 4into1 yoshimuri and a K&N filter

Thanks
Frank

Set your a/f to 2.5 turns out.

Then re-test. If that doesn't fully resolve the symptoms, then clean the carbs again... paying close attention to the pilot circuit.

Then reassemble and check for any air leaks really well.

Sync....

Test again, and report.

Krey