Help FCR idle trouble

[Some Dude]

I can't seem to get my fcr 41's to idle.   Should I be able to do this with just the fuel mixture screw & air screw?  I've tried adjusting both but the bike won't idle unless I open the fast idle screw about 5 turns.  I've tried 55 and 60 slow jets, both with the same results.  my engine mods are listed in my signature, along with pod filters and sil conical exhaust.  I also have pederzini 1.1 ign modules.  I bought these carbs used they are synched and the floats are adjusted to 9mm.  Is there somehing i'm missing?

here's what i have in the fcr's now.
slow jet  60
slow air jet 60
main jet 160
main air jet 200
needle EMT
clip  3rd from top

Thanks

                                                                                                                                                                                         

[Howie]

Fast idle screw? 

[Some Dude]

Fast idle screw? 

Mabye it's the choke, it's the screw on the side that opens the slides just a little bit

[knightrider]

um, there is no choke.  approx. how open are the slides at idle? maybe you just need to open em up a tad. turn the little plastic knob on the left side, my slides are open a couple mm i would say without accually going out and looking.

[Some Dude]

um, there is no choke.  approx. how open are the slides at idle? maybe you just need to open em up a tad. turn the little plastic knob on the left side, my slides are open a couple mm i would say without accually going out and looking.

that's the one i'm talking about i've been riding with it that way for a couple months but, i figured when it was properly jetted that would remain closed.

[knightrider]

no that is your idle adjustment. its mostly a set and forget item, unless you need to adjust it for an extremely cold startup, i myself never touch it and never have had a problem starting my bike cold, but i live  in socal so it doesnt exactly get cold here.

[printman]

Was having horrible times keeping mine idling,

The symptoms were, it would idle way above the setting like stuck in advance ignition ( 1800 )
then would drop to below the setting, if it wasn't given throttle it would die

An extreme rich condition will give lean symptoms. look for the dropping in idle
a lean condition will surge upwards most times

A 60 slow maybe to rich and a 55 maybe to lean, I'm running a 58 with one turnout on

and 5 down on the needle. When playing with the ignition timing it made differences in the ways the fuel settings were set, more fuel here, less there.

With the 944 kit, check your ignition timing, may need to be less advanced with the high comps, I'm at 4deg BTDC

[akmnstr]

I'm having a similar problem.  The engine will not immediately come down to idle.  I have fiddled with the adjustments and found the best settings but still not working properly.  I have torn apart my carbs and cleaned them, and changed the slow fuel jet.  Checked for vacuum leaks, negative results.  Tomorrow I'll check the slides to see if they are in synchronized.   There is not much left to do except tear my hair out.  I'll keep watching this thread to see if there are other ideas. 

Could these problems be the result of worn valve guides?

One suggestion that I was offered was the weak stock coils, but some dude has aftermarket coils. 

[Speeddog]

I'm having a similar problem.  The engine will not immediately come down to idle.  I have fiddled with the adjustments and found the best settings but still not working properly.  I have torn apart my carbs and cleaned them, and changed the slow fuel jet.  Checked for vacuum leaks, negative results.  Tomorrow I'll check the slides to see if they are in synchronized.   There is not much left to do except tear my hair out.  I'll keep watching this thread to see if there are other ideas. 

Could these problems be the result of worn valve guides?

One suggestion that I was offered was the weak stock coils, but some dude has aftermarket coils. 

Sync 'em, that's probably the issue.

Someone posted up a link to a cheapo DIY manometer a little while ago.

[oppet]

Fcrs are straight pull carbs, you cannot sync them with vacuum.
Heres good one http://www.factorypro.com/tech/carbkei.html

Edit.. I had also this flying idle when stopping on lights, it hanged while then settled down.
Chanced slow jet from 62 to 60 and now its stable.

[akmnstr]

Fcrs are straight pull carbs, you cannot sync them with vacuum.
Heres good one http://www.factorypro.com/tech/carbkei.html

Edit.. I had also this flying idle when stopping on lights, it hanged while then settled down.
Chanced slow jet from 62 to 60 and now its stable.

Thanks, I've had that guide to tuning FCRs in a binder for years.  Good stuff in there.  I've also had this problem for years and
will do the drill bit synchronization.  There is not much left to try except

[dlearl476]

I can't seem to get my fcr 41's to idle.   Should I be able to do this with just the fuel mixture screw & air screw?  I've tried adjusting both but the bike won't idle unless I open the fast idle screw about 5 turns. 

Are you confident in the state of tune the motor's in?  I ask because I just installed 41's on my otherwise stock motor (so my jetting won't be any help to you) and I had the idle screw almost all the way in in order to get a decent idle.  I went out of town a couple of weeks ago so I thought I'd take the opportunity to drop the bike off and have the valves adjusted and belt tension checked and when I got the bike bike once it warmed up it was idling very high and took a LONG time to return to 1K.  I backed the idle screw down and it's running great now.

Moral of the story: first, I don't think it's neccesarily bad if your idle screw is turned in 5 turns, if the bike is running properly and second, the adjustment of the valves may be playing a part if you don't know their in spec.

[Some Dude]

I actually have the idle thing figured out and it was running very well until yesterday morning, when I went to start it and there was no spark in the vertical cylinder.  Last night after work I checked a few things and found out, now I have a bad ignition module.

[dlearl476]

Dude, that sucks.  Do you know why?

[Some Dude]

I'm not sure why When I shut it off the other night I heard a pop and I didn't think much of it, but now i think it might have been an electrocal problem of some sort.