The International CBX Owners Association

Today i finally got the 79 running, after a fashion, after having the carbs rebuilt.
But I've got some questions I'm hoping somone can answer for me,
So here goes..

I believe it is not firing on all 6, and the 2 inside cylinder exhaust pipes are 80-100 degrees cooler than the other 4, would that indicate not firing, or is that normal? I would have thought they'd be the hottest.

What is air pressure in forks supposed to be, i see no mention in the manual?

I went only 1 kilometer, slowly, 1st gear, the steering seemed VERY heavy , is that normal?

Is it possible for the tach to read wrong? It idles about 2000 according to Tach, but does not sound anywhere near that high to me. The tach needle moves seemingly fine, but doesn't return to 0 when stopped, unless you tap gauge.
I did change the tach previously as the needle on the original had broken.

I appreciate any help offered.

Hope i've got this in the right section.

Thanks

Hi ya, John.
All six pipes should be the same temperature. If you are sure the carb cleaning was successful i would be checking the plugs for spark on 3 and 4.
I run 10 psi in the forks. The usual limits are 7-13 psi. '79 forks did not have air...which forks do you have?
Slow steering is a tough one. Do you have a comparison? They are big, top heavy bikes. Going slowly is not one of their strong suits.
The tachs can get temperamental but it is often the cable or the drive. The tachs themselves can get dried up or dirty inside but access to the inards is difficult.

All these little snags will just make you appreciate your X even more when you get things sorted.

Hi John

So you know, every CBX has 3 independent ignition circuits, each serving two cylinders as follows: 1&6, 2&5 and 3&4.
So, if your 3 & 4 are way cooler (and the way you describe it, it certainly feels so), it is quite possible the corresponding ignition circuit needs attention.

Cheers, Aris

At the risk of stating the obvious, heavy steering is likely caused by low front tire pressure.

Rick Pope wrote:At the risk of stating the obvious, heavy steering is likely caused by low front tire pressure.

My first thought, so i checked it, and brought it up to spec.

steve murdoch icoa #5322 wrote:Hi ya, John.
All six pipes should be the same temperature. If you are sure the carb cleaning was successful i would be checking the plugs for spark on 3 and 4.
I run 10 psi in the forks. The usual limits are 7-13 psi. '79 forks did not have air...which forks do you have?
Slow steering is a tough one. Do you have a comparison? They are big, top heavy bikes. Going slowly is not one of their strong suits.
The tachs can get temperamental but it is often the cable or the drive. The tachs themselves can get dried up or dirty inside but access to the inards is difficult.

All these little snags will just make you appreciate your X even more when you get things sorted.

I don't know what the forks are, I thought they were stock, but the bike has many little mods to make it a better rider, done by previous owner.
I don't believe they are prolink models as they are 35mm tubes.

Steering i'm comparing to my BMW and a 82 1100 Katana. Both good size bikes.

I'll pull the tach cable and lube it, see what happens

Kool_Biker wrote:Hi John

So you know, every CBX has 3 independent ignition circuits, each serving two cylinders as follows: 1&6, 2&5 and 3&4.
So, if your 3 & 4 are way cooler (and the way you describe it, it certainly feels so), it is quite possible the corresponding ignition circuit needs attention.

Cheers, Aris

I'll look at that, is there any thing in particular i can test or check?

johnod wrote:

Kool_Biker wrote:Hi John

So you know, every CBX has 3 independent ignition circuits, each serving two cylinders as follows: 1&6, 2&5 and 3&4.
So, if your 3 & 4 are way cooler (and the way you describe it, it certainly feels so), it is quite possible the corresponding ignition circuit needs attention.

Cheers, Aris

I'll look at that, is there any thing in particular i can test or check?

Sure, start by checking that there is spark in the 3 & 4 spark plugs. If so, probably your 3&4 problem lies elsewhere (carburation?).
If there is no spark, then begin working backwards into the ignition circuits, first swapping coils around to see if the problem moves to another set of cylinders.

But, I would recommend you get a Honda service manual ASAP. It is full of insightful information as well as wiring diagrams and schematics. It is worth its weight in gold and you will eventually find the problem(s).

Aris