Honda CG idle issue

Okies, so I'm fixing up the CG I got back a few days ago, and I've hit a slight snag.

The bike was running fine, but was idling a little rough, so I put a bit of fuel additive into it. I then changed the bars over (so the throttle cable was disturbed), and restarted the bike. It was fine for a bit, but then I noticed that if I turned the bars fully to the right that the idle would increase. While trying to feed throttle cable back into position, the bike started idling at a very high speed, with the idle-screw doing nothing to change it. The choke is also not stuck on.

Now, I've since taken the tank off and found the point where the throttle cable meets the carbs, and removed the cable from it, and the idle is still high. There's another cable that runs somewhere into the carb-top, but I can't find what this does (and the haynes manual completely ignores it).

I have a question, then: Could it just be the fuel additive making it go wild? There wasn't a massive amount of petrol left in it (maybe 2-3 litres), and I put about a capful of Pro-FST in it, so I'm assuming the ratio should be quite high. Just don't want to go fill it up with fresh fuel if I don't have to, as the tank is going to be on/off a lot in the next few weeks and I'd like to minimize weight and spillage (which I'm prone to doing).

I doubt the pro-fst stuff would do that, however if you think it could be a cause, drain it and run it on what's left on the carbs till it's out, then stick a couple of litres of fresh stuff in and see, although it seems something is up with the throttle cable since it started being a problem when you were doing stuff with it. GL with the problem, it seems fairly minor.

Ok, an update:

Changed the petrol over to new stuff and also checked the throttle cable. The cable is completely fine - I can disconnect it fully from the assembly on the bar and it's slightly slack, and checking at the points it connects to the carbs on the outside (little lever/rocker mechanism), there's a small amount of free-play here, so it's not pulled taut at all. The throttle-valve assembly is similarly free of tension, so I'm assuming the cabling is ok.

End result: Turning on the bike now results in an instant redline. Yesterday with the old (and I'm assuming gammy) petrol it was idling probably at about 3-4krpm by the sounds of things. Today it's going way past that.

Any ideas?

[Dave20046]

tried oiling the cable? Sounds like it's stuck on. Have you took apart the carb(singular ) and checked it?
I would check the movement in the slider and also clean out the float bowl and check the float. If your floats sticking it'll affect something doubt it'd have the full throttle affect you're experiencing though.

Have oiled the cable, but the movement in it was free anyway. The slider's sliding freely, no problems. Only thing I can think of is indeed taking the carb apart, but was really hoping to avoid that as I've never done it before. Looks like it's going to be an interesting Sunday project.

Any other ideas for what could do it? Would an air leak possibly cause this?

[Dave20046]

Originally Posted by Neeja

Have oiled the cable, but the movement in it was free anyway. The slider's sliding freely, no problems. Only thing I can think of is indeed taking the carb apart, but was really hoping to avoid that as I've never done it before. Looks like it's going to be an interesting Sunday project.

Any other ideas for what could do it? Would an air leak possibly cause this?

luckily the cg carbs aren't bad to get to and work on iirc. Would be a massive leak to redline it! Sounds like the actual slider's stuck on open or something, but I'm not sure my experience is limited. Make sure everything's tight though, use a bit of silicone sealant if you've got some lying about and it's a worry/doesn't seem quite right.

Resolved now: Stripped the carbs+cleaned, and reseated everything nice and tight, and the problem's completely disappeared. Oddly enough, the bike no longer picks up if I turn the bars to full-right-lock, even though I've not touched the cable, so I'm a bit unsure why it ever happened when I did it before.

[Dave20046]