The International CBX Owners Association

After spending the best part of a day trying to source the infamous no 80 (0.013") drill bit to clean my 79 CBX Z idle jets which were well and truly clogged, I tried another method which for me at least, worked well.
I stripped some dead normal domestic multi strand electrical wire and cut some individual strands, 2" long each measuring at 0.009" to 0.011".
Now these are seriously soft copper wires but I found that if I eased one end gently down the jet hole in a circular motion using some carb cleaner in the process, ALL blocked jets eventually opened up nicely!
The process was finished off by squirting plenty of carb cleaner through them to seemingly clean them further, fully unblock the jets.
Now these copper strands are slightly thinner than the optimum 0.013" and dead soft - there is no way they could damage the tiny hole of the brass jets. And they did seem to work for me ...
Any thoughts?

If you do not remove them and visually see that all the orfices are clean you'll alway wonder if you got them completely clean. If you're already this far into them, I would go ahead and remove them. You don't want to get the whole bike assembled and not have it idle correctly because of a clogged jet. Just because you're getting carb cleaner through the jet doesn't mean that its all clean. Just my 2 cents.

Frankly I had no idea there is so much to them and definitely see your point.
Now getting them out is another story ...
Thanks for the great pics.

Kool_Biker wrote:Frankly I had no idea there is so much to them and definitely see your point.
Now getting them out is another story ...
Thanks for the great pics.

There are threads of information about tapping and removing them with a #40 screw.

Yes, found and read some after your reply above, and I am now at it.
Thanks again.

The little buggers are out.
And it was well worth the effort, as two of them were quite clogged. SanDogDewey, thanks for the suggestion!

Good Job Kool Biker! Love those dirty pics. It really feels good when you get it back together and it works well.

Congrats - Steve

Kool_Biker wrote:The little buggers are out.
And it was well worth the effort, as two of them were quite clogged.
SanDogDewey, thanks for the suggestion!

Nice job! Now you can blow out that passage much better with them out. A cheap set of paint gun cleaning brushes will get most of the residue off the sides of the passages. If you have access to a ultrasonic cleaner, a few cycles with each carb does wonders. Its amazing all the crap that comes out of them.

Thanks guys.
And if I may also add my 2 cents worth here, for all those not in America (SAE) or Britain (BA), and only access to metric tools:
1. After lots of measurements; I found a middle M2.5 hand tap, through a small brass guide, was optimal for cutting threads into the top of the jets in question. 2. The guide was made of a small piece of 6mm brass, slightly tapered on one side to sit snugly on top of the jets, with a 2.5mm through hole to locate the tap accurately and make the job easier. 3. A longish M2.5 screw, brass spacer, washer and M2.5 nut could then be used to pull the pilots out. 4. Although I found I could cut safely up to ~5.5 mm, I did not find it necessary to go beyond 4.5mm which on a M2.5 corresponds to plenty of threads.
5. All 6 pilots came out a treat! No heat and no undue force were required at any stage - very satisfying! 6. Once out, one catch I could see, was cleaning the treaded side of the jets EXTREMELY WELL, as they were FULL of the tiniest pieces of brass from the tapping operation, each one of them capable of clogging the tiny .35mm jet orifice . I cannot stress this enough! 7. A gazillion thanks to my good friend and great micro machinist Dimitri Mangakis, who helped, guided me and gave me the confidence to do this delicate piece of work.

Hi Kool Biker.

Great write up with lots of good pictures, just what we need.

Cheers
Chris J.
p.s. over here we also use metric nuts and bolts (can't remember the last time I used B.A. screws) Cheers

Joner wrote:Hi Kool Biker.

Great write up with lots of good pictures, just what we need.

Cheers
Chris J.
p.s. over here we also use metric nuts and bolts (can't remember the last time I used B.A. screws) Cheers

Ditto what Chris said, fantastic contribution to the site, thanks so much for that and the top quality photos. We need more of this.

N.

It is a great pleasure,
I certainly get more out of our site, than I try to put in!

Regards
Aris

Thanks a lot for this, Aris!
We seem to have more and more members who are so good with writing reports about repair/restoration jobs and illustrating them with excellent pictures!
It would be great if you send a short e-mail/pm to Jan Ringnalda, the club prez, in order to have that material collected for the CBXPress and preserve it in print!
I know, to some of the "old guard" this may be last year's snow and has been done and talked about many times, but I see there is a constant influx of new CBX owners.
The majority of those who were members of and supported the club in the earlier years are no longer here, no longer interested and don't even own a CBX anymore.
Let's make sure the "new generation" is being helped and supported with know-how!

Hi EMS!
It is always a pleasure to help with this excellent site, as I progress restoration of my 79 Z.
Of course what I do is very much part of a 'learning process' for me as well, I am certainly no professional.
Thanks
Aris

Someone may have already mentioned this, but a heat gun will usually melt even the hardest clog out of a pilot jet. It just bubbles right out (you can also clean bothersome carb body passages like this sometimes). Just clamp the jet very lightly in a vice and heat it right up. You'll need to clean the residue out, but this will open up those rock-hard clogs that take forever to "drill" through with a fine wire.