Blocked idler jet, how did you unblock it

[Revvy Kevvy]

This machine was sitting for 10 years, all full of gasoline and just pushed into a garage and left.

I am stripping it and rebuilding it bit by bit, today was the carburettas, the whole thing was just gunged up with black stuff and green stuff, god knows what it is but I have cleaned it and mostly it seems ok.

My idler jets are completely blocked at the end, no needle can be pushed through it from top to bottom. I am pretty sure its supposed to have a hole all the way through. The tiny little side holes that I guess are to mix air into the mixture are ok, but lengthwise its a total blockage.

Anybody had this before and solutions? I was going to drill it out but the smallest drill I have is 1mm and I suspect its smaller than that. Whatever is in the hole is hard and black and like metal.

 

[CaptChrome]

I would soak the jet in the strongest solvent you can find for 24 hours and then try pushing a small diameter wire through (old wound guitar and violin strings work great for this). Where I live, I can get pretty strong fuel injection system cleaner at my local auto parts store. I have been successful with this alone. However, given different environmental regulations, I am not sure what you might have available to you, but perhaps the staff at an auto parts store might be helpful.

If that doesn't do the trick, escalate the soak by using an acid (muriatic acid is a good first choice and is available at places that sell pool chemicals around me) The acid will not damage the brass jet, but should destroy any organic stuff plugging the jet. Just be very careful, read up on precautions when using acid and wear the eye and skin contact protective equipment.

 

[Revvy Kevvy]

Captain Chrome, thank you for your perfect answer.

I am in the far north of Sweden and I dont think there is a swimming pool for 1000 miles around me but I do have a automotive shop called BilThemia about 60 miles south so I will pop down during the week and see if they have any fuel injector cleaner or when I drive past my local gasoline pump check in there.

I was trying to get a needle from the wife's sewing kit in the hole but your suggestion of some gutiar wire or violine string shows how small that hole is so I am glad I did not try ramming the 1mm drill bit in...the jet has some numbers on the side so I guess that shows its size and assuming its in metric it starts with 0. so less than 1mm.

I hate getting old as my eyes cannot see so well but I can at least take some happiness in the fact I know what points are and I have played with carburettas when I was much younger....

Again thanks Captain Chrone and long may you continue to shine.

 

[tstidham]

I also had this same situation with blocked everything in my 78 xs400. I used lots of brake clean on the metal parts (keep it away from the diaphragms) and a single strand of 12 gauge copper wire to ream out the jets and carb body passageways. And for the ultimate win, they now make safety glasses with a built-in bifocal reader lens. I have the 3x magnifying ones and they're a god send!

https://www.google.com/search?q=bifocal+safety+glasses+3.0&client=firefox-b-1-m&sca_esv=5493436b52351d30&sxsrf=AE3TifO1OmrbfNZLiCD7ZpdkKoctZNEu6w:1754310702335&ei=LqiQaPmbFM7tptQP4bm0mAw&oq=bifocal+safety+glasses+3.0&gs_lp=EhNtb2JpbGUtZ3dzLXdpei1zZXJwIhpiaWZvY2FsIHNhZmV0eSBnbGFzc2VzIDMuMDILEAAYgAQYkQIYigUyBRAhGKABMgUQIRigATIFECEYoAEyBhAAGBYYHjIGEAAYFhgeMgsQABiABBiGAxiKBTILEAAYgAQYhgMYigVIyzdQ-BhY5i5wAXgBkAEAmAGFAqABpgWqAQUwLjMuMbgBA8gBAPgBAZgCBaAC8QXCAgoQABiwAxjWBBhHwgINEAAYgAQYsAMYQxiKBcICChAAGIAEGEMYigXCAgUQABiABMICDRAAGIAEGEMYyQMYigWYAwCIBgGQBhGSBwUxLjMuMaAH9BWyBwUwLjMuMbgH5AXCBwUzLTQuMcgHRg&sclient=mobile-gws-wiz-serp

 

[Revvy Kevvy]

Oh you and I are the same. I have been using the brake clean also on the carburetta and it seems to work very well. Captain Chrome gave me the idea of using acid (or injector cleaner) I was unable to find it close to me but I decided to give white vinegar a shot and it worked really well.

I have bees up here and to make the bee frames we use wire, this wire turned out to be perfect for pushing through the jet hole. So now I have two nice clean idle jets and everything else is also clean and clear. If in doubt I used petrol as a solvent as well as brake cleaner.

I broke the bowl gasket on assembly so sadly I will need to buy one of those, but otherwise I think the carby should be fine. Love this idea of the bifocal safety glasses, thats now on the shopping list too especially if I manage a USA trip before the end of the year.

 

[CaptChrome]

I am in the far north of Sweden and I dont think there is a swimming pool for 1000 miles around me

Ah yes, probably too cold for pools, besides they would probably be used by moose and reindeer more than by people. The far north might be some great riding territory for an XS400 though!

Great news that you got the jets unplugged. Onwards!