Topic: Proper slide opening for bench sync?

[kenolds]

Can anyone give me a good general guide for how far the slide should be open when idling?  This is just for a bench synch.  I realize it will need to be tuned once installed.  Also, what is a target fuel height in the bowls?  I have set the float height as best I can, but I am suspect that the fuel in the bowl may be running a bit low.  ( This is for a CB200, but I figured it would be similar for a SOHC-4).

Thanks,
Kenolds

[Bankerdanny]

One of your slides should be non-adjustable (typically the #2 carb). use that one for reference.

[Bankerdanny]

whoops, I didn't even see that you were asking about a twin.

I'm not sure that it really matters. See which one is lowest and match that one.

[kenolds]

I am trying to diagnose a running problem.  What is the typical gap when a bike is idling?  Is it 1/8"  or .010" ? 

Kenolds

[Scott S]

 I don't think there's a specific gap or size to use. Use a fairly small drill bit to bench synch them (which can be done on the bike with a CB200. I just helped a buddy do his).
 You'll have to adjust the idle screw then to get the proper idle. After that, adjust the idle air mixture screws. Go in until it stumbles, then back each one out for best idle. Set them at ~1.5 turns out to crank it, then adjust them.

 All of this should be done after a proper tune up: valve and cam chain adjustment, fresh plugs, set points gap and timing, etc. Carbs should be done last.

[kenolds]

Thanks Scott.

I have done everything that you mentioned.  All completely sound advice and what I assumed would result in a proper running bike.  However, the bike doesn't idle at all.  It will not run without continuing throttle "revving" even with the idle screws turned all the way in.  When I hooked up my carb synchronizer gages, they barely registered any vacuum with the slides open about .125" to .150" (just guessing on the measurement).  Any suggestions?

Kenolds

[tbpmusic]

Float level on CB200 is specified as 21 mm.
Mixture screw at (nominally) 1-1/4 turns - this can vary if you've changed mufflers or air cleaners.

Have you checked your compression?? I'd hope to see 140-150 psi or so on a CB200.
Sounds like you have lousy compression to me............if so, you're wasting your time messing about with the carbs. Make sure your valves aren't too tight and your ignition timing is dead on.
CB200's are also prone to sticky spark advancers.

[mrbreeze]

Have the carbs been rebuilt or at least cleaned well? If your slow jets are plugged....she ain't gonna idle.