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Carburetor study with microscope plus Smarter Every Day video

Jun 30, 2021#1

Joe Kuhn

I once got a mower to run by spraying out the carb with cleaner. It ran, but it surged some, so my son said to give him the jet. He put it under a microscope and we saw all kinds of fuzz around the hole. We had to change the focus some to see the extent of it, but it was clearly dirty still. Here's what it looked like with red arrows pointing at the dirt in one I happen to have laying around today. This one is not bad compared to the one causing the surging.

I cleared the dirt with a jet cleaning tool so that it was nice and smooth looking under the microscope. The surging stopped. Here's the tool:

Here's the setup I had to use to take the picture above.

The white thing is a piece of tape.

And here's the video. Darn good video. Have fun.

Jun 30, 2021#2

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bertsmobile1

You are right about the surface of the jets which is why jets are sized with end mills or 4 flute jet drills to give a smooth bore.
However the blue pack are tip cleaners which are files and should never be used for jet cleaning as you can easily make a round hole into an oval or funnel the ends .
Always better to use actual drills between your fingers as the flutes do not cut under finger pressure

Jun 30, 2021#3

Joe Kuhn

bertsmobile1 said:
You are right about the surface of the jets which is why jets are sized with end mills or 4 flute jet drills to give a smooth bore.
However the blue pack are tip cleaners which are files and should never be used for jet cleaning as you can easily make a round hole into an oval or funnel the ends .
Always better to use actual drills between your fingers as the flutes do not cut under finger pressure

Drills like these? I like that concept and I happen to have a set of these. Will use them, but the spun wires bend easily, so not a lot of pressure can be applied. And the wires are round, not with sharp edges. Plus I'm careful when I use them. The purpose is to remove debris, not increase an inside diameter. Will change that photo above to just the spun wires.

Jul 1, 2021#4

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bertsmobile1

No they are just micro drills
But they are really good for cleaning
Jet drills go about $ 20 a pop

Jul 1, 2021#5

Joe Kuhn

bertsmobile1 said:
No they are just micro drills
But they are really good for cleaning
Jet drills go about $ 20 a pop

Ok, these must be what you mean as they are made to be used by hand.

Jul 1, 2021#6

B

bertsmobile1

Yep and they ain't cheap

Jul 1, 2021#7

StarTech

I actually use the micro bit for resizing jets here but most I use them just clean up a jet that corrosion. If it is a new jet that I haven't already size check they are for that purpose too. With jets being size in .001 mm there will times that a bit will not work as well. Sizes like 115.5 (1.155mm) are out there.

Jul 2, 2021#8

Joe Kuhn

bertsmobile1 said:
Yep and they ain't cheap

I'll stick with the twisted wire tool. Thank you very much.

Jul 2, 2021#9

B

Born2Mow

You are ALL crazy ! The jets on tiny carbs found on small engines are so finely tuned that any metal object will gouge the soft brass and make the engine run richer. Just because you get away with it doesn't mean it's not happening. Just because you can't see it doesn't mean it's not happening.

If you must stick something in there, then use a soft wooden object, like a fat wooden toothpick designed for serving Hors d'Oeuvres. Like These.

Jul 2, 2021#10

S

slomo

Born2Mow said:
You are ALL crazy ! The jets on tiny carbs found on small engines are so finely tuned that any metal object will gouge the soft brass and make the engine run richer. Just because you get away with it doesn't mean it's not happening. Just because you can't see it doesn't mean it's not happening.

If you must stick something in there, then use a soft wooden object, like a fat wooden toothpick designed for serving Hors d'Oeuvres. Like These.

You tell them B2M.

I use monofilament fishing line. No chance on screwing up my brass jets. 2-4lb on pilot jets and 10-30 on mains.

slomo

Jul 2, 2021#11

S

slomo

Even using a drill bit with your fingers will enlarge the orifice.

Drill bits are hardened steel. Jets are soft brass. Not a good match.

slomo

Jul 2, 2021#12

B

bertsmobile1

slomo said:
Even using a drill bit with your fingers will enlarge the orifice.

Drill bits are hardened steel. Jets are soft brass. Not a good match.

slomo

Total and utter crap
Get a # 65 micro drill and try to cut a B &S jet biger
If you press hard enough you will get 1/2 turn in and the drill will jamb and most likely break.

And you can drill a hole through brass with a wooden stick and some sand if you try for long enough.
If the debris in the jet is hard, then forcing it through with any blunt object can and will cause the debris to score the sides of the jet which is just as much trouble as enlargement or obstruction.
The idea behind twisted wire jet cleaners and cleaning with jet drills is to break away the debris then transport it down the tool through the flutes.
In order to CUT you have to have a CUTTING EDGE and that EDGE has to be SHARP.
Carbide is harder than wood and steel but try to push a masonary drill into a lump of steel, wood or even brass and all you are going to do is make a mess burn the wood and melt the brass .
Having tuned carburettored engine for better than 50 years I can saftely say you are talking trash
Firstly fishing line is fine for pushing rust or fine dust through a jet
But it will not shift varnish or corrosion debris
To cut a jet with an undersized jet drill is next to impossible unless you put it into some sort of machine
Jet drills are high strength boron steel very similar to a mower blade and quite flexible
They will follow the easiest path which will always be what is obstructing the hole, not the jet unless the drill has a bigger diameter than the hole in the jet.
Brass is not marshmello

Welding tip cleaners are FILES and they are designed to remove tiny bits of metal that have been blown back up the pipe & welded onto/ into the copper, corrosion debris that has melted into the copper , carbon deposits that have alloyed with the copper and fluxes that have solidified .

While they can be used to clean carb jets with they can & do enlarge the jets, particularly in the hands of people without the fine motor skills in their hands developed from years of carefully cleaning a jet.

Brass is used to make jets for one and only one reason
It machines very cleanly with the correct tooling so the sides of the hole are smooth enough not to cause interfearence with the flow of whatever is being metered through it.
BAck in the old days they used bronze and bronze requires honing to get the same surface finish even when machined fully submerged

So for the average mug at home then a set of micro drills is more than good enough provided they start with a small one then work their way up .
Your chances of cutting the jet bigger with a drill bit between your forfinger & thumb is a long way less than zerro where as the chances of distorting or enlarging the hole using a file is quite high
If you want to enlarge the jet in a controlled way then jet drills are the go

Jul 2, 2021#13

Scrubcadet10

Jul 2, 2021#14

Hammermechanicman

While we all have our favorite method to clean jets. Some of which have been blessed by angels and others which will result in the end of life on the planet. One of the uses for the torch tip cleaners is to slightly open up the main jets on these new mowers that are so lean they surge. I know the hole is not perfectly round but the fuel molocules seem to get through just fine. I have fixed a dozen or so this way. EPA is probably in a panic by now.

Jul 2, 2021#15

B

bertsmobile1

I do deliberately enlarge jets from time to time on engines where they are just running too lean
Had Titan which was blistering plugs till I took the left main jet out 2 sizes.
That took a long while to figure out and ultimately I had to use the colortune & camera to confirm my suspicion.

Jul 2, 2021#16

Scrubcadet10

Hammermechanicman said:
While we all have our favorite method to clean jets. Some of which have been blessed by angels and others which will result in the end of life on the planet. One of the uses for the torch tip cleaners is to slightly open up the main jets on these new mowers that are so lean they surge. I know the hole is not perfectly round but the fuel molocules seem to get through just fine. I have fixed a dozen or so this way. EPA is probably in a panic by now.

was that a knock on the door, i heard?

Jul 3, 2021#17

StarTech

Hammermechanicman said:
While we all have our favorite method to clean jets. Some of which have been blessed by angels and others which will result in the end of life on the planet. One of the uses for the torch tip cleaners is to slightly open up the main jets on these new mowers that are so lean they surge. I know the hole is not perfectly round but the fuel molocules seem to get through just fine. I have fixed a dozen or so this way. EPA is probably in a panic by now.

Hammer, They are on their way for I am a dirty rat fink.

But seriously you do need to be careful cleaning jets. Here I use hand drill that came with my torch tip cleaning set. And are not the file type but is actual micro drill bits. I have broke them most cleaning my cutting torch tip. Now I need to get a new set for the torch work. I do keep torch and jet drill bits separate. I have since collect about half of the number bits for jet resizing here or just to check the size of new jets so I can create a jet size vs part number cross reference guide I use internally here. Since no one seem to able to help me with this it is done as I run across new jets. It beginning to become useful so don't need to resize a jet by hand but just the next size on my chart sometimes.

For those that use wire probes just know what you are doing as not all holes are though ones some have check valves.

Jul 3, 2021#18

Joe Kuhn

Born2Mow said:
...any metal object will gouge the soft brass and make the engine run richer...

How do you know this? I've not seen any metal on my spun wires. Will have to look closer and report back.

Jul 3, 2021#19

StarTech

Joe Kuhn said:
How do you know this? I've not seen any metal on my spun wires. Will have to look closer and report back.

Even paper will wear stainless steel. I replaced enough paper guides over the years. Even the fuel can wear the jets over time.

Jul 3, 2021#20

Joe Kuhn

StarTech said:
Even paper will wear stainless steel. I replaced enough paper guides over the years. Even the fuel can wear the jets over time.

I believe you are correct, but that kind of time is not a factor here. I'm just trying to get the crud out of the jet so it will stop surging after I put the carb back together. My metal cleaners did that for me per my son's microscope before/after views. We did NOT see any metal bits - and we looked closely, closer than you can see with your eyes because we were using a microscope.

Jul 3, 2021#21

Hammermechanicman

StarTech said:
Even paper will wear stainless steel. I replaced enough paper guides over the years. Even the fuel can wear the jets over time.

Been there and done that. Amazing what 20 or 30 million sheets will do to metal parts that are supposed to never wear out.

We got the "best oil" thread
We got the "best sparkplug" thread
Now we got the "best way to clean a small hole in a piece of brass" thread

And to avoid controversy i will keep my method to myself. ?

Jul 3, 2021#22

S

slomo

For carb jets, carb spray is for the varnish slash fuel deposit mess. Fishing line helps open the hole without enlarging. Zero chance of enlarging with nylon fishing line. You guys can use all the steel drill bits and torch tip files you like. Not on my oil burners.

slomo

Jul 3, 2021#23

Beamster

On a related topic, I had a brand new motorbike that sat on the dealer's floor with gas in it for over a year. As expected it had running issues when I got it. Try as they may, a more qualified dealer could not clean the carbs properly enough to resolve the issues but a set of new carbs (under warranty) made it new again. I learned that "poke, prod and spray" may never fix crudded up carbs.

Jul 3, 2021#24

Hammermechanicman

40kHz water is your friend.

Just had a black SUV drive past my house rwice.

Jul 3, 2021#25

G

Gord Baker

Born2Mow said:
You are ALL crazy ! The jets on tiny carbs found on small engines are so finely tuned that any metal object will gouge the soft brass and make the engine run richer. Just because you get away with it doesn't mean it's not happening. Just because you can't see it doesn't mean it's not happening.

If you must stick something in there, then use a soft wooden object, like a fat wooden toothpick designed for serving Hors d'Oeuvres. Like These.

Take your meds.

Jul 3, 2021#26

Scrubcadet10

Hammermechanicman said:
40kHz water is your friend.

Just had a black SUV drive past my house rwice.

Lock n' Load

Jul 3, 2021#27

StarTech

slomo said:
For carb jets, carb spray is for the varnish slash fuel deposit mess. Fishing line helps open the hole without enlarging. Zero chance of enlarging with nylon fishing line. You guys can use all the steel drill bits and torch tip files you like. Not on my oil burners.

slomo

Hammermechanicman said:
40kHz water is your friend.

Just had a black SUV drive past my house rwice.

Well there are times they necessary no matter what you do. But most time the USC does the job. Either way no cleaning method is perfect. There are times it is a combination of them that is needed. Of if you just install a China Junk on the engine is it a good that one or more of the jets will need reworking. Just did one about a month ago where the idle jet was a couple sizes too small.

And Hammer see what you get by opening your big mouth. Here back in 70's and 80's Redstone communications would roll out there radio hunters trying to caught us guys operating out of band but we had our own spies watching for them. When we knew they was patrolling we go to the in between the legal channels to talk. Of course I wasnt supposed to have 135 am channels on the 40 am channel CB radio either.

Jul 3, 2021#28

E

enigma-2

I've used carburetor jet cleaning tools set for rodding out jets. Designed to clean jets without damaging them. Cheap as well.

Amazon.com: 1 Pieces Tip Cleaner Set Carb Carburetor Jet Cleaner for Cleaning Welding Cutting Nozzles/Tips, Gas Orifices, Sprinklers and Shower Heads, 12 Wire Set : Tools & Home Improvement

www.amazon.com

Jul 3, 2021#29

Hammermechanicman

Gord Baker said:
Take your meds.

Jul 3, 2021#30

S

smalltowntex

I always used "tip drills", use to get them at a good welding supply. Back in the day when you could clean a plugged up oxy/acet cutting tip with those drills they were handy then also.

Jul 3, 2021#31

Hammermechanicman

StarTech said:
Well there are times they necessary no matter what you do. But most time the USC does the job. Either way no cleaning method is perfect. There are times it is a combination of them that is needed. Of if you just install a China Junk on the engine is it a good that one or more of the jets will need reworking. Just did one about a month ago where the idle jet was a couple sizes too small.

And Hammer see what you get by opening your big mouth. Here back in 70's and 80's Redstone communications would roll out there radio hunters trying to caught us guys operating out of band but we had our own spies watching for them. When we knew they was patrolling we go to the in between the legal channels to talk. Of course I wasnt supposed to have 135 am channels on the 40 am channel CB radio either.

I have it on good authority that more than one alphabet agency has had you under surveillance for quite some time.

And this coming from a guy who actually used to do intelligence gathering for the NSA in the 70's

Jul 3, 2021#32

Scrubcadet10

Hammermechanicman said:
And this coming from a guy who actually used to do intelligence gathering for the NSA in the 70's

i swear i lost everything i had in a boating accident.... So NOTHING to see here....??

Jul 3, 2021#33

Hammermechanicman

Scrubcadet10 said:
i swear i lost everything i had in a boating accident.... So NOTHING to see here....??

I will add that to your file.

Jul 3, 2021#34

Scrubcadet10

Hammermechanicman said:
I will add that to your file.

Jul 4, 2021#35

Joe Kuhn

Got me a new digital microscope to take some better pictures. Look at the resolution on the threads on this new Briggs main jet.

I'm wondering what torch tip cleaners really look like up close...

Jul 4, 2021#36

Joe Kuhn

Here's a side hole on that Brigg's jet. It's nice and clean.

Jul 4, 2021#37

Joe Kuhn

Here's a torch tip cleaner compared to a round file I happen to have in my shop. Torch tip cleaner is on top, round file on the bottom.

Big difference. Torch tip cleaner is basically flat with grooves cut in it while the round file has flares.

Jul 4, 2021#38

B

bertsmobile1

They are still files

Jul 4, 2021#39

Joe Kuhn

I'll have to purchase some cleaning drills for comparison.

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Carburetor study with microscope plus Smarter Every Day video

Amazon.com: 1 Pieces Tip Cleaner Set Carb Carburetor Jet Cleaner for Cleaning Welding Cutting Nozzles/Tips, Gas Orifices, Sprinklers and Shower Heads, 12 Wire Set : Tools & Home Improvement

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