The International CBX Owners Association

Thanks Spencer and Dave.I have allready ask help from Kool Rider .I will take the carbs to him next week.But i think its good to share a rare carb situation .
I will post Kool rider answer ASAP.
Thanks again

You are a lucky fellow to have Aris so close by. He is as we say in English, 'like a dog with a bone' when it comes to troubleshooting.

Great support Aris!

akis1962 wrote:Thanks Spencer and Dave.I have allready ask help from Kool Rider .I will take the carbs to him next week.But i think its good to share a rare carb situation .
I will post Kool rider answer ASAP.
Thanks again

When you figure out the problem, be sure to come back and tell us all what you found.

Thanks for the kind words Nils.
Akis has contacted me, we'll link some time soon and look forward to checking out these carbs.
We will be reporting back, of course.

Earlier on today I had the pleasure of having Akis with his CBX carbs rack in my den ..

On the bench, we first made sure carb no 4 was not bound or limited in its travel by any other part of the rack.
We then tried to adjust its throttle valve by way of adjusting and tightening of the throttle valve securing screws.
Despite all our efforts the throttle valve could only be made to close to a point where some light (shone from the back) would go past the bottom of the valve to body area as shown in the pic below. Akis has informed me that the throttle valve in question is not the original.
The parts manual does not list a spare part number for the throttle valve leading me to assume they are matched to the individual bodies during assembly and are not meant to be interchangeable ..
Before going further, I wonder how serious this is and how the situation can possibly be improved.

Cheers, Aris

Aris:

You can interchange throttle plates. I'm assuming it's not in backwards, but might fit better turned upside down. Or try a different one, if he has spares. Alas, the carbs will have to be separated to fiddle with that. It does appear that fitment of the throttle plate is the problem.

Dave

OK, I think we are getting somewhere ...
Earlier on today I separated the 4,5,6 carb trio from 1,2,3 giving me the opportunity to check alignment between the 3 carbs; it was all over the place.
Next, the 4, 5 & 6 trio was laid on my granite surface plate and the 3 carbs were aligned between them properly, as per manual.
This had the immediate effect of smoothing out the throttle shaft rotation.
However, and despite my efforts to adjust, the offending number 4 plate continued passing some light, as per earlier pic.
So I removed the no 4 plate to may be put it upside down and ... bingo. Once flat on my granite surface plate it was found to be bent! Ever so slightly, but most certainly bent.
Tomorrow Akis will bring an old, damaged rack of CBX carbs. Hopefully I will be able to salvage a good throttle plate from these, to try on carb body no 4.
Cheers

So earlier on today, Akis arrived with 2 boxes full of old CBX carbs in various stages of decay (which he should bring) and a big box of sweets (which he absolutely shouldn't have ...).
I salvaged a throttle valve from the boxes which looked OK and at the very least was not bent, and had it on carb no 4.
Big improvement, but still not 100% happy.
So I removed the valve, again, and had a close look at the no 4 throttle shaft only to find perceptible play, see pic, may be .2 or .3 of a mm by feel, in the vertical axis, which to me at least seems excessive. Not sure how much of this could be tolerated in operation.
Any thoughts?
Cheers

Throttle shaft play or no play, the 4,5,6 trio were put together, again, and carefully adjusted to provide what is in my eyes at least, full closure of the slides, as well as perfect synchronism between opening and closing and a smooth operation.
Considering these are old pretty worn carbs, I am happy with the outcome.

So no more "4th carb out of sync" issue for Akis, and we can conclude original problem was a combination of the bent no 4 slide (had to go through few of his spare slides to pick a nice one), and partially misaligned carbs bodies. Next steps, in my opinion, would be for Akis to dismantle everything (without uncoupling the bodies), meticulously clean each and every part and then put together under surgical cleanliness conditions.

In fact I will lend him Randakk's excellent multi hour video on the refurbishment of the Honda GL1000 carbs (brilliant, has helped me no end, thanks Randall), from where he can pick up ALL the tricks he needs to end up with a reasonably well operating carbs rack. But I will have to discuss all this with him upon his return to Athens from a family break.

Best, Aris

Aris:

Akis is so lucky to have your guidance in solving this. Once in a while a set of carbs will give me fits as well and it takes a lot of fiddling to get them right. Give me an unmolested set to rebuild, no matter how dirty they are, any time over a set that several guys have used a 'hammer and chisel' on. I think you have this set fixed finally!

Dave

What Dave said, hope that passed for a little bit of fun for you Aris, great support.

N.

Guys, I am still at 'that' early stage, where all this is great fun!