Hanging Idle 73 z1 900

Hi all new member here
i have a 73 z1 all stock have an issue with hanging idle
it will stay at 2400 rpm then drop to normal idle 
new intake rubbers
carbs ultrasonic cleaned vacuum balanced
could choke assembly be causing the problem original seal rubbers or any other suggestions  ?
thanks in advance
Mike

Mike there are two distinct different "types" of hanging idle. One being a leaking manifold other being an over-rich condition but burning it off slowly keeps idle too high. A vacuum leak doesn't generally go away, over-rich does. Double check your fuel level first. If choke plungers, i have a trick for that too. These ramp style carbs are finicky to start with and any glitch in the array of multiple springs/seats/levers can make things worse. Also if carbs have been "gone thru" make sure the jet holders haven't been over tightened. I warped, even slightly can grab the slide jet needle and keep it's slide from fully seating. Keep us informed.     

No mention of synchronization of the carbs? Did you sync them. Never mind I see you balanced them. What tool do you use.

You could try slackening off the cables to eliminate a mechanical issue 

   Old grease in the advancer, under the points cam where it rotates on the advancer shaft can become very sticky with age, preventing the points cam from retarding when idle drops.  This can keep timing advanced artificially, which will keep idle high.  Disassemble the advancer, clean & lube under the cam and around the shaft with high-temp grease.  If you remove the advancer weights to clean & lube the pins, be careful not to stretch the springs.  Too, those tiny C-clips on the pins can get away easily, so take your time doing the R&R.

Good Ridin'
slmjim & Z1BEBE

Hi
amazon vacuum gauges 
 

Thanks for the help
i set float hight manually I will get the tube gauge 
what is your trick with the choke ? I was going to buy new assemblies ?

 

Thanks
i did do that and no hanging slide
i did not check needle hight
has always been cold blooded and needed choke for some time 

Thanks I did not consider that
 

Im assuming you calibrated those gages to one vacuum source. 

Hi
yes all set on one carb 

P48ker wrote:

could choke assembly be causing the problem original seal rubbers or any other suggestions  ?

 

Yes if they are OEM from 1973.