Topic: Should I be able to see through my idle jet?

[shads]

Im in the process of rebuilding my PD46A carbs (from a 77 550).  Everything so far has cleaned up amazingly well with a combination of soda blasting, pine sol soaks and an ultrasonic cleaner.  All the brass looks great, however I can't see through the idle jets, nor can I poke any wire through them or blow through them.  All four are the same, fine guitar string enters a couple of mm into each end but then wont go any further.

There was a lot of hard varnish in the bowls and all over the jets so I wondering if I should just be replacing the idle jets?

[brewsky]

Yes you should be able see thru them if you hold them just right up to the light.
They can be a bear to clean since there is a chamber of sorts inside.
I have used seafoam, carb cleaner and boiling water with simple green on some and have eventually got them open.
I use a single strand of lamp cord wire to ream them

[Don R]

 If there's liquid in there you can't see through, could be dried fuel.

[Bodi]

Definitely should be a hole that you can see through.
Be very careful poking things through them. The jet number is the size in hundredths of a millimetre... what gauge/diameter is your string wire? Using a steel wire is not good, copper is softer than the brass and won't damage the jet orifice.
Soak them in carb cleaner or maybe acetone and/or lacquer thinner.
Try  to clean and reuse them, aftermarket jets are problematic.
Many pilot/idle jets have an attached emulsion tube with several cross drilled holes. Make sure these are clear if you have them. Same goes for the needle jet emulsion tubes.

[shads]

Thanks guys! They are current soaking in carb cleaner.

I've only been trying to poke nylon guitar strings through so should be ok, not sure of the size but its the bottom string on a guitar so its very fine.  Like I say, it does go in both ends but only a couple of mm.

I'm going to have to buy new OEM main jets anyway from JetsRUs as the bike will need re-jetting (it also currently has Keihin jets in carb 1 and 2 and aftermarket jets in 3 and 4 for some reason  ), so its not a major issue if I have to get replacement Keihin idle jets too.

[Bankerdanny]

Swing by a guitar shop and pick up some E string. It is thin and stiff enough to clean the hole without damaging the jet

[shads]

Ummmm...

I've only been trying to poke nylon guitar strings through so should be ok, not sure of the size but its the bottom string on a guitar so its very fine.  Like I say, it does go in both ends but only a couple of mm.

[Bankerdanny]

Use the string, then some carb cleaner, then again with the string spinning it between your fingers like a drill bit. Slowly but surely the cleaner and string will work their magic.

[BomberMann650]

Ummmm...

I've only been trying to poke nylon guitar strings through so should be ok, not sure of the size but its the bottom string on a guitar so its very fine.  Like I say, it does go in both ends but only a couple of mm.

The nylon e-string is thicker than the steel e-string.

Berrymans Chem Dip is also good for restoring jets to "like new" condition.

[shads]

Use the string, then some carb cleaner, then again with the string spinning it between your fingers like a drill bit. Slowly but surely the cleaner and string will work their magic.

Will do..! 

[Deltarider]

As long as - whatever you use - is not harder than the brass. Steel is harder than brass and therefore a no-no. I used stranded copper wire as shown in pic. Widely available, cheap  and effective.

[brewsky]

Here is a cross section sketch of the jets.
Note that the critical and smallest opening is hidden inside

[Deltarider]

When in doubt (like: did I do it right, did the PO treat them right?), replace by genuine Keihin brass.

[TwoTired]

The slow jet is .42 millimeters in diameter.  So, you need a wire smaller than that to poke through it. Or, something smaller than .016 inch.
A steel high E guitar string of 0.010 works. But, you need to be gentle.  And it is best if you round off the end of the wire with file or abrasive paper.

Cheers,

[david 750f]

Listen to the previous posts. Clean everything meticulously. Blasting and ultrasound doesn’t always work.

[DaveBarbier]

Can you heat up the jet with propane to help crumble the varnish away? I’ve done that to some stubborn pilot jets and it seems to turn the varnish to a powder. Floss with wire and finish with chemicals.

[DaveBarbier]

Same way I clean my teeth. Propane, floss, chemicals.

[BobbyR]

The slow jet is .42 millimeters in diameter.  So, you need a wire smaller than that to poke through it. Or, something smaller than .016 inch.
A steel high E guitar string of 0.010 works. But, you need to be gentle.  And it is best if you round off the end of the wire with file or abrasive paper.

Cheers,

+1 I was to happy with the wrong sized steel string once. Bike started up really quick without the choke. Problem was raw cas was shooting out the pipe. Proper sized string  with rounded end and gently applied.

[Deltarider]

I don't see why one would risk it using a steel string (which costs money) and then have to be gentle, where stranded copper wire is free, effective and safe.

[shads]

Thanks for the input everyone - after multiple soaks in carb cleaner, boiling water and lots of poking they don't look any different from when I started.  Think ill just get new ones to be on the safe side when I buy the main jets....

[BomberMann650]

I don't see why one would risk it using a steel string (which costs money) and then have to be gentle, where stranded copper wire is free, effective and safe.

For the guitarist in the shop.  It's more like "recycling" the couple inches of string that are snipped off the tuner gear.

[JamesH]

I use these (0.4mm for ‘40’ idle jet)

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F132588499895

Get some white vinegar in a cup/mug - put in the microwave until it starts to boil.

Remove from microwave and drop the jets in - leave for a few minutes.

Then remove and try clearing the jet with the tool above..

[Deltarider]

$ 7,- for a new one (genuine Honda).  http://www.davidsilverspares.co.uk/parts/by-part-number/partnumber_991240760400/

[brewsky]

$ 7,- for a new one (genuine Honda).  http://www.davidsilverspares.co.uk/parts/by-part-number/partnumber_991240760400/

I have not been able to find a honda part number for the push in slow jets for PD carbs?

[brewsky]

I don't see why one would risk it using a steel string (which costs money) and then have to be gentle, where stranded copper wire is free, effective and safe.

For the guitarist in the shop.  It's more like "recycling" the couple inches of string that are snipped off the tuner gear.

+1
You can also unwind a few loops of a thicker string, bend an L or J  shape out of the core and use it to remove those pesky washers and o-rings from PD mix screw holes