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.

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.