Another 81 brought back to glory

[pgilliam1]

About the high idle,
There could be few reasons, vacuum leak, sticking cables,not properly adjusted floats, sticking slides etc.
I found few holes in my airbox boots when I took the carbs off which apparently came from previous carb cleaning.
Previous owner had told me that the mechanic who cleaned carbs could never get bike running right and most likely this was the cause.
I patched all holes using inner tube repair kit.
Every symptom that you are having points to your carbs, clean them!

I hear you loud and clear. Very particular, these carbs. Will this kit be all I need if the boots are OK:
http://www.ebay.com/itm/131106008055?ss ... 1423.l2649

[EMS]

Some have reported negatively about the kits form cuizininmage. I have a couple of them but have not used them yet. The only thing you really need when cleaning carbs are new seals and gaskets. Buying complete kits with all new jets may be a little overkill. The only critical "hardware" are the float valves and they are supposed to be not that good from most aftermarket suppliers. Best are original Honda and I think they are still available.
Look what Randakk has to offer.

http://randakks.com/

[cross]

Full rebuild kit is definitely not needed.
I ordered kit from randakk that came with gaskets, seals, auto valve and accelerator valve diaphragms.
If you find jet or two bad or they get damaged while removing, you can always buy what you need.
One more advice would be to get an inline fuel filter.
Randakk also sells them but you can get inexpensive one at any local motorcycle shop.
But if you can get a hold of carb sync gauges, do what Dave had suggested, sync them first!

[pgilliam1]

Full rebuild kit is definitely not needed.
I ordered kit from randakk that came with gaskets, seals, auto valve and accelerator valve diaphragms.
If you find jet or two bad or they get damaged while removing, you can always buy what you need.
One more advice would be to get an inline fuel filter.
Randakk also sells them but you can get inexpensive one at any local motorcycle shop.
But if you can get a hold of carb sync gauges, do what Dave had suggested, sync them first!

Yeah, I will take Dave's advice and find a shop that can gauge sync them before I rebuild. There are a few private garages here in St. Louis that work on older bikes. I called the closest Honda dealer to me and they said they don't work on bikes this old. How nice is that.
I did install an inline fuel filter. THX.

[pgilliam1]

Some have reported negatively about the kits form cuizininmage. I have a couple of them but have not used them yet. The only thing you really need when cleaning carbs are new seals and gaskets. Buying complete kits with all new jets may be a little overkill. The only critical "hardware" are the float valves and they are supposed to be not that good from most aftermarket suppliers. Best are original Honda and I think they are still available.
Look what Randakk has to offer.

http://randakks.com/

I've read other threads here that mention they liked what that website offered. I'll check them out. THX.

[asacuta]

If you're going to sync your carbs, set your valve clearances first. This may not be so important if your carbs are way out of sync anyway, but after I set my valves, my carbs seldom need much tweaking.

[daves79x]

Good point Al, and one I think was made pretty early on in this discussion. The old axiom - 'A CBX was rarely parked because it ran perfectly', holds true most of the time. On a bike of unknown maintenance history (which is just about any one you find these days), you really need to start at square one and check everything. Opening up the valve cover is most important. Flitting here and there, chasing one glitch after another, leads to more frustration than anything.

But I understand the impatience to 'get the thing running'. You will be eventually doing all the stuff you should do sooner or later, so might as well go through everything now. As I said before, you need to have, or develop, at least enough mechanical ability to understand and do the basic maintenance to these, because you won't likely find anyone in your area that you can trust to do it. Even carb rebuilding can be mastered, but be prepared to take some lumps doing it. Sending them off to someone that can do the job quickly and correctly might be a good option for you, but you still have to master removal/installation.

I think we've outlined pretty well what WE'D do if the bike were ours, I guess it's up to you to decide how good you want the bike to be.

Dave

[pgilliam1]

Thanks to everyone for all your inputs. I'm getting to know this bike better every day and from what I've gleaned from your experience I'm sure at this point that I need to adjust the valves and cam chains and clean and sync the carbs. I find the service manual leaves some of my questions unanswered as I go through it, so all I can hope is that my future questions will continue to have the support you all have shown so far.
Thanks Again -

[pgilliam1]

Messing around with the bike today and for some reason I decided to feel the headers while it warmed up a bit. Well, the #4 header (third from the right) was cold, and stayed cold, while the others got really hot. So, obviously there is no combustion going on in that cylinder. I replaced the spark plugs about 200 miles ago and while riding I didn't notice any miss, but it must have been there. I pulled the wire off the plug while the engine was running and it had no effect at all (the wire had good connection to the plug as I could feel it come off).
Other than swapping the spark plug with a known good plug, what is the most common fault for this condition on these bikes? Any known weaknesses like coils, wires, etc.? I wonder if this has something to do with my idle problems - DUH!

[pgilliam1]

I've really messed something up. I started the engine with plug #4 out. I attached the plug to the wire and was going to ground it to the engine to see if I had spark. I started the engine and the noise was so bad that I shut it off. I reinstalled the plug and restarted the engine. It now has the worst/loudest tapping sound coming from near that cylinder I have ever heard. What have I done?

[cross]

What kind of sound is it?
Maybe your spark plug cable is not on correctly.
Can you record and post the sound?

[EMS]

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