Topic: Help in diagnosing CB200 poor running condition

[kenolds]

1974 CB200 with aftermarket headers, mild porting, and stock filter housing with foam replacing the paper elements.  Had poor running/ idling problem.  Rebuilt carbs with Keyster kits and Kreemed tank.  No help.  On advice from Honda twins "expert" re-ringed, bored, new pistons, lapped valves.  Cleaned carbs again (third time).  Still will not idle without twisting grip even with throttle stop screws turned all the way in.  Timing checked, points adjusted, new condenser, new plugs, new plug wires.

What is going on?  It will run if you continually rev the engine.  It will take you around the block.  I want to do a carb synch, but  feel the problem goes deeper than that.  Is there anything other than re-re-re-cleaning the idle circuits that anyone can recommend? When running, it pops and burbles constantly.  I put a slightly larger jet than stock in it this last time.  If you open the carb slides just a bit more than the throttle stops are able, it will run steadily at about 2,200-2,500 rpm without dying.

Any suggestions are greatly appreciated.

Kenolds

[tbpmusic]

CB200's are very sensitive to exhaust/air filter changes.
You'll probably need to get a box of new spark plugs and invest some time into re-jetting/needle tweaking.

[kenolds]

I was afraid of that. Will headers and air intakes greatly affect idle? The headers were on it when I got it, so for all I know, it has never run right with them.  They look pretty sweet IMO, but may dictate poor running.  They had a "hooker" sticker on them, but I have no idea if that is the real manufacturer, or just a sticker.
 I hooked up my carb synchronizer gages today and they hardly registered any vacuum at 2,000 rpm. It could be due to leaky connections on my gages.  The slide stops are still all the way in, so there is about a 1/8" gap below each slide.  It actually ran fairly smoothly when I started it today, but after 1-2 minutes of running, I noticed cylinder two exhaust pipe was still cold.  My next plan of action will be to verify proper fuel levels in both float bowls.  What is a recommended next step?  It seems idle mixture screw adjustment might be in order, but how do I do that if it won't run with the slides lower than 1/8" or so...
Thanks,
Kenolds   

[MoMo]

The idle circuit on 200 and 185 Hondas can be really difficult to clear.  After the pilot jet is removed you need to run a fine guitar or  piano wire up through the idle passage.  That was my experience with the last 200 I worked on...Larry

[kenolds]

Thanks for the reply. Since it looks like I'll have the carbs off again... would it be better to install original Honda jets, Keyster replacements of stock size, or Honda oversize jets (don't remember actual sizes right now) and why?

 I guess I'll take those cars off AGAIN and clean them out again.  Last time I made certain that air and/or aerosol can carb cleaner would squirt through all passages.  But, it sure seems like there is still blockage.  I'll report back when I have rechecked them.

Kenolds.

[mrbreeze]

I just posted in your other thread about cleaning the carbs. I don't know about the 200 twin but I do know most people here don't care for the needles that are supplied in the Keyster kits. Actually...... most of us that know anything about carbs don't care for Keyster kits period. I did my 750 carbs a few years back with K&L kits from Dennis Kirk and I used everything but the needles (ran my OEM needles).

[kenolds]

Thanks Mr. Breeze.  I'll try reinstalling the original needles and see how it reacts.  The good news is, it pulls pretty strong at WOT.  It just pops and burbles anywhere below.  I still haven't received any info about a typical slide opening at idle.  Anyone....

Kenolds

[tango911]

Do a full tune up.  Clean the carbs and all.

CB200
   
Float setting
21mm

Air Screw turns out
1.250
   
plug type
D8HS/X24FS

Plug gap
mm /  inch
0.6-0.7/0.024-0.028
   
Points gap
mm / inch
0.3-0.4/0.012-0.016
   
Valves Intake and Exhaust
0.05/0.002

[kenolds]

For anyone searching this thread in the future... the problem was that my carb slides were installed backwards!  Once they were turned around (by swapping which carb they were inserted into) the bike ran better.  Still not fantastic, but enough to ride and hopefully tune now.  Somehow, I don't think it pulls as well at WOT with the slides in correctly - should I try one forward and one backwards... just kidding!   Next, I will do a carb synch and then play around with jets and needle heights.
Thanks for the help everyone.

Kenolds.

[grcamna2]

You'll work out the fine tuning and it'll run good w/ LOTS of jetting work  .