Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

One of my local shop told me they soak the carburator in a acid fluid over night to clean everything before rebuilding.  Wondering if that is what the professionals' common practice.   If that is the case what kind of acid do they use?  I do have a bucket of acid that I use to clean car parts.  I am worry it is too strong to clean the carburator.

What kind of carb?

I usually wash the exterior of the carb with a solvent to get grease  and grit off then I open it up.  I clean every orifice, gallery, and jet with a very thin piece of wire.  Stripped trash bag ties work good.  After the wire treatment, I spray WD-40 into everything the wire went and ensure I have fluid passage at the other end of the hole.  Then I blow everything out with compressed air, wipe out the float bowl and put it back together.  Pretty easy if you're familiar with cleaning carbs.  Getting the jets out sometimes takes a bit of finesse and the correct tools.  Other than that it's pretty straight forward.  Try to find a diagram for the carb before taking it apart.  It will help understand how it works.

Most carburetor cleaning problems I encountered over the years were easily accomplished by a can of spray carburetor cleaner.  I would ususlly remove the carburetor swish it around in a can of clean gasolibne till anything in or on was loosend, brush it with a bristle paint brush (nylon bristles tend to dissolve in things like gasoline and carb spray)to remove dirt, etc, then blow it out with an air compressor nozzle.  At this point the spray carb cleaner can be used to loose and remove all things the gasoline and brush could not both inside and outside the carb.  be generous use the whole can of spray and the carb will be clean as a whistle by the time you're done.  If not it must be rebuilt or replaced, in which case all you invested was a can of carb cleaning spray.  I have never had to either replace or rebuild once I did the cleaning procedure I just described, and simply replaced the carb which I blew dry with the air hose. Hope you find it useful.

Cleaning is not usually done with acid.  strong acids will severely corrode metal, it being why you see signs on tanker trucks that read, "CORROSIVE", it is a warning.  Anything that can dissolve metal usually burns human tissues severely, especially eyes. Carburetors are cleaned with solvents, not acids.

I agree with new yorker.  My lawn tractor crapped out this spring and I did the thing with carb cleaner followed with a compressed air blowout and it did the trick perfectly.  But watch the carb cleaner - its fairly toxic - better to use it outside.

I use a similar procedure to borat's.  I use a spray carb cleaner and a small acid brush with the bristle cut short to clean off the outside first.  Remove the bowl, float and needle.  Remove the idle mixture screw (even the ones with the plastic cap)
Spray carb cleaner in all the passages.  Then run a twist tie wire in the three tiny holes in the throttle bore by the throttle plate.  In what ever type of main jet it has and the idle jet passage.  Flush with carb cleaner again.  Then blow out all the passages with air.  Clean the bowl, shake the float.  And put a very, very light coat of grease on the top lip of the float bowl.  I very rarely replaced any parts
except maybe the bowl gasket.  Be careful about blowing compressed in the gas line connection tube.  You can blow the rubber needle valve seat right out of the carb.  Try finding one of those when
you have no idea which direction it went.  There is sometimes a third very tiny hole in the threads of the main jet bolt.  Don't miss that one.

>>One of my local shop told me they soak the carburator in a acid fluid over night

 

   They did not literally mean “acid” or probably it was your choice and intended to generically  mean some stuff that ate away gum and dirt in a carb.

 

>>>Wondering if that is what the professionals' common practice.

   Most shops use a one gallon of can solvent dip or ultrasonic bath with a light soap/detergent.  You can get a can of solvent that comes with a small dipping basket at most auto parts places for $20 to $40.  A good ultrasonic tank for small carbs is $2000-$2500.

 

    What the other posters have said is all good advice and they may never have run into a problem.  Gas does not do much for gum and the same for carb spray.  For very nasty carbs those are not enough and the dip able to soften and loosen gum poking can’t reach.  If you’re doing 20-50 carbs a season dipping helps you avoid the occasional removing of a carb that’s not quite clean.

I've seen people mention that Harbor Freight sells some small ultrasonic cleaners. I think they may also be able to heat the liquid during cleaning. I seem to recall reading that they can be had for around $40 sometimes with a coupon. Some people apparently use them to help clean their carbs, etc, even in a homeowner-type setting. So there is at least some sort of inexpensive ultrasonic solution, for occasional use.

    As an alternative to going to dip I picked up an HF ultrasonic with heater, their good one, and used it on many carbs.  I can't say it made any difference over many carbs.  I'd still end up with an occasional carb I'd have to do again.  I eventually went to dip and rarely have a problem.  I do quite a few carbs and many that are very old with weird buildup of white, grey, light green, dark green, tan, brown and deep brown.  The only time I use ultra now is on very nasty carbs after the dip in hopes it might shake out some crud the dip loosened in interior passages. 

   One local dealer went to ultra two years ago and says that's all he uses now.  His tank cost $2500. 

It seems like I have read that many carb cleaners will damage the gaskets and rubber O-rings. Seems likely that the cleaner might also damage any rubber seats or needle tips that it comes in contact with.

As with many things, knowing what you are doing is probably a good idea.

Comments from the experts????

   

>>It seems like I have read that many carb cleaners will damage the gaskets and rubber O-rings.

 

   Carb sprays don’t damage gaskets and O-rings.  If you’re doing a quick cleaning and get spray on gaskets and O-rings it evaporates so fast there is no effect.   For a bench cleaning or dip those parts are removed and don’t get juiced.

 

   It’s rare to have to pull an emulsion tube on a Tecumseh engine and they never have a problem with spray or dip.

 

   Plastic connectors on some carbs at the gas line carb port get left on during a dip and are never affected. Thye not affected by spray.

 

>>>Seems likely that the cleaner might also damage any rubber seats or needle tips that it comes in contact with.

    Needle tips and seats are usually removed for a bench cleaning or dip.  For a quick spray the spray evaporates so fast there is no affect.

Nothing beats complete disassembly , probing with a thin wire, flushing with a spray of your choice (mine is WD-40) and blowing out with compressed air.   Every possible orifice, hole, gallery, channel, opening and jet must be known to be clear prior to reassembly.   Otherwise, you'll be doing it again until everything is clean.  I've learned that there is no shortcut to a clean carb and I've cleaned a few.

I learned early on that no stone can remain unturned when cleaning a carb or you will be doing it again and again.  As Boart said disassemble and clean every hole, nook and cranny flush with wd40 or your choice of cleaner and blow every orifice out with compressed air, taking note not to blow the rubber seat for the needle and seat out.

When cleaning one for the first time recently, I soaked the carb (minus the plastic and rubber pieces) in a glass jar with Berryman B-12 Chemtool. It was inexpensive, and it was Walmart had for liquid carb cleaner (not sprays). I'd read about some people suggesting using that for soaking them.

Does anyone have experience with how well the B-12 typically works for that application? I think it's meant more as a Seafoam-type fuel additive. But, again, it was just what I had access to while I was at the store.

RedOctobyr wrote:
No experience with B-12. 

I don't expect the fluids I use to do any of the actual cleaning.  Gasoline is a pretty potent solvent.  If it doesn't dissolve it's own residue, I doubt that there is much out there that will be very effective without some form of  physical cleaning.  I would not trust any concoction to clean a carb on its own.  The only reason I use WD-40 is because I keep a supply of it on hand.  I use the fluid not so much for cleaning as much as confirming that the passage/orifice/jet are clear.  When I spray the fluid in one end, I want to see it come out at the other.  That, plus the flushing effect is all I use the fluid for.  The primary cleaner is the piece of thin wire.  I use it to loosen any debris that may be in the passages/orifice/jet then flush and blow with compressed air.  Using a liquid on it's own will not be nearly as effective as probing/flushing and compressed air.

To flesh out the thought, yes, I also used a lot of spray carb cleaner, some little picks & hooks (not for jets, just for getting gunk off the carb body, etc), and two different diameters of copper wire, for running through openings and passages. Sprayed carb cleaner through each hole to make sure it came out the other side, and used compressed air as well. The only passage I could not get the wire to go all the way through (coming out the other end) was the idle jet/passage, on the engine side of the throttle plate. I could run the wire into it ~2", starting in the flow path by the throttle plate. And I could get it to go into the hole by the main jet, but I couldn't get it in far at all, just into the hole. I think that passage maybe takes a turn right at the hole, so maybe that's why.

The engine runs now, so this pretty much worked. But it does hunt/surge a bit when sitting with no load (it has no throttle control, it's at 4000 RPM). I understand that could be due to it running lean, or having a partially blocked idle jet/passage. And that's the only one I couldn't really confirm was fully open. The carb is not adjustable at all. I'm not sure that the o-ring between the plastic emulsifier tube and the main jet is sitting where it's supposed to be, it slipped out of its groove while installing it, and is somewhat between the end of the tube, and the top of the main jet. I'm hoping the engine will smooth out when I can put a load on it (today's possible-snow turned out to just be rain).

I soaked it in the hopes that the cleaner could help deal with anything internally, which I couldn't really reach (such as the idle jet/passage).

at full throttle and no load it is not unusual for the engine to hunt as it is bouncing off of the governor at 4,000rpm.  I suspect it will smooth out under a load. 

You can start it up and load it by putting it in gear and holding back on it to see if the load of holding it makes it smooth out but I think it will be fine when blowing snow.

regarding carb cleaning you could make a small tank and add an air line to it made out of 1/8" copper tubing like they use for ice makers in refrigerators.mount a brass shut off valve in line near the tank and then hook the other end up to an aquarium air pump.place your parts in the tank,add enough fluid to cover the parts,and then open the brass valve allowing the air to enter near the bottom side of the tank.you can control the amount of fluid adgitation by the opening or closing of the valve.i use a similar set up to adgitate powder paint for making fishing jigs.don't know why it wouldn't work for carbs.i would guess it would roll a quart or so of fluid pretty easy depending on the size of the air pump.

RedOctobyr wrote:
Gasoline is a very good solvent for many things, like grease, oil etc that are non-polar, but, as you mention, obviously not for the kind of deposits that clog your carb.   But, when exposed to oxygen in the air for long periods, gasoline fuel oxidizes to more polar things that deposit in the carb.  To dissolve these, you need a more polar solvent ie some kind of chlorinated material (carb cleaner), acetone would probably work too.  BUT...most of these solvents are toxic so it is important not to be breathing the solvent fumes when you do the cleanup.

That's ...... ahhhh.......grim.  Real grim. 

Looks like something took a dump in it.  Disgusting.