Topic: Cleaning pressed in Pilot Jets

[Johnny340]

I have two pilot jets that are blocked and I can't seem to clear them with compressed air and carb cleaner.  Even on the ones that flow air, I can't pass a wire around the corners of the passage.  Any ideas how to clean them?

[harisuluv]

Compressed air and carb cleaner won't cut it.  They need to be physically cleaned with a proper sized wire/guitar e-string. 

You need a smaller wire. 

[Johnny340]

I have all wire sizes and even the smallest doesn't go around the corner of the cleared pilot circuit (3 are clear now).  The last one is frustrating..  I can feel the wire go past the pilot jet and then, like the other the clear ones, it stops at the corner of the passage.  They are recessed which also makes it hard to get to.  From the other side I can get the wire in the four holes associated with the pilot circuit of each of the 4 carbs the same amount as well.
Anyway, here's a pic.

[flybox1]

why not remove them first?
did you also remove and clean the emulsion tubes?

[BobbyR]

+1  They are easily removable and you can do a better job cleaning them.

[harisuluv]

+1  They are easily removable and you can do a better job cleaning them.

Are you thinking of PD carbs?  These are DOHC carbs, the jet he is talking about has no slot for a screwdriver, and is pressed into a tube in the body of the carb itself.  How would you remove that?

[flybox1]

no access thru the top to press it down and out?

[kslrr]

You can remove pressed in jets by clamping on Vise Grips and gingerly rocking/twisting/pulling until it pops out.  Press it back in the same way.  I've done this many times.

[flybox1]

You can remove pressed in jets by clamping on Vise Grips and gingerly rocking/twisting/pulling until it pops out.  Press it back in the same way.  I've done this many times.

I'm pretty sure these are CV carbs 

[RevDoc]

You can remove pressed in jets by clamping on Vise Grips and gingerly rocking/twisting/pulling until it pops out.  Press it back in the same way.  I've done this many times.

I'm pretty sure these are CV carbs 

Yes, James and Flybox, you are both right. Those are VB series carbs. Same as I have on my '82. Best way to clean the low-speed circuit is with an ultrasonic.

[grcamna2]

You can remove pressed in jets by clamping on Vise Grips and gingerly rocking/twisting/pulling until it pops out.  Press it back in the same way.  I've done this many times.

+1  done it a number of times myself.

[mystic_1]

Have another look at the pic, gents.  Don't think you're getting any vise grips down in there.



OP, if your wire is making it past the slow jet but getting hung up at the corner of the passage, have you tried rotating/spinning the wire as you're pushing it in?  It also sometimes helps to put a little bend in the end if the wire, if you can, so that it'll tend to glance off of the corner in stead of digging into it.

mystic_1

[RAFster122s]

The jets can be removed but you have to have a high quality ez-out from snap-on or matco. If it breaks you can be buying a new carb body (most likely).
You should remove the jets to get them good and clean. The jets can have a pocket of debris  beyond their tip. You will often see a white deposit as well as other deposits.

The emulsion jets in the main jets sometimes won't be clean by just ultrasonic,  a numbered drill that fits the holes in the jet are needed to chase the holes. Just don't want to see brass shaving in the cleaning process.  The bit will just fit through. You can fill the debris but it is difficult to see much after it is clean. It does make a difference.
My CX500 has CV carbs and I think it also uses the VB but the VB26 comes to mind.

David

[grcamna2]

Honda makes a special carb. jet cleaner tool w/ numbered size wires made of stainless steel for different size jets all the way down to #35.When you use that it keeps you from going too far when you push the wire through;if you want a part# for the tool let me know.

[flybox1]

VB's with air cutoff diaphragms, like on the DOHC CB750/900/1000
(If so, those will need to come out and be verified good)

Cleaning the VB slow speed Jets. Once you get it clear with an E string. . . remove the air cutoff diaphragms from each carb body.
Grab one of those red carb cleaning straws laying around your workshop, and some black electrical tape.
build up one end of the straw with tape so that you can cram it into the slow speed jet hole,
remove the mixture screw and all its tiny bits, and attach the can of spray carb cleaner to the other end.
Put on some safety goggles.
One finger over the primary jet hole, another over the hole under the air cutoff diaphragm if there is one, and spray the carb cleaner.
If the circuit is clear, you should get bubbles or better out of the mixture screw hole.

[RAFster122s]

The air cutoffs will be toast if used a soak or spray of carb cleaner on them...it doesn't like rubber.
There's a guy who sells cutoffs on eBay along with cx, gl, and goldwing parts. Forgot his name at moment.
There's two different styles of air cutoff valves,  be sure that you order the right ones for your carb.
You can get deceleration backfiring when they are bad. Easiest method for identifying one that is leaking or bad. The rubber breakdown and gets very thin over time...eventually ripping.

The cutoffs were around 20 $ usd each a couple years ago when I did my cx carbs.

Glass beading the exterior of the body gives a nice matt stock like finish on the carb bodies and you can polish the bowls and domes to a high luster if you wish.  A purple chemical cleanrr like Castrol Super Clean can strip the clear coating off the domes if yours has partially come off.

[flybox1]

The air cutoffs will be toast if used a soak or spray of carb cleaner on them...it doesn't like rubber.

Correct!  Amended my above post to be succinct.

[RevDoc]

The air cutoffs will be toast if used a soak or spray of carb cleaner on them...it doesn't like rubber.

Correct!  Amended my above post to be succinct.

When I first brought Eva home & started the rehab on her I spent some time over on the 750Custom forum reviewing carb procedures. Several members recommended using Non-Chlorinated Brake Cleaner on the carbs instead of the usual spray carb cleaner. It does a good job of cleaning and the Non-Chloro isn't as nasty if it gets on some rubber seals or gaskets. Not as toxic for you as well!

Also, here is a link to a superbly illustrated & organized carb cleaning manual for the VB carbs. It was very kindly made available for those who want to do the job themselves or, at least get an idea what they are in for before they tackle the job!

http://www.cb750c.com/modules.php?name=Forums&file=viewtopic&t=13611

[Duanob]

This is an issue with the CX500 carbs. There is a how-to over on that forum. It's not for the faint of heart.

This is a blurb from the CXForum.com

"I have been successful removing them by first tapping the jet with 4-5 threads of 4-40, then using a nut and washer arrangement to pull the jet out. Use a bit of heat to help the jet break loose, and don't tap too deep."

The actual Jet part of it is further down so there is room to thread into the jet body.

[RAFster122s]

Duan, you mean this is an issue with the VB model CV carbs with pressed in pilot jets.  The removal is difficult and easy to screw up if you break an easy-out in them. The threaded tapping into the jet has been used by a few successfully.  But, it really makes a difference you can feel following Larry's process as outlined on the CX/ijGL forum.  The bike runs so much smoother and throttle response is better because the carbs are working correctly.

David

[Johnny340]

Thanks for the replies!  Yes, there is no substitute for an ultrasonic cleaner.  I got the one from Harbor Freight and it worked like a charm.  After 4 cycles the stubborn pilot circuit was clear!  I took everything apart , cleaned brass and replaced o-rings and breather T's.  It's like new now.
On assembly, I see that someone has replaced one of the float valves with one that's too short.  At least those are still available from Honda.