I see lots of posts on here regarding carburetors with the classic goo-pile in the float bowl.  I'm sure many of you are familiar with that green-black slop that accumulates in the bowl, pilot jet, main jet and emulsion tube after two or three years of sitting with fuel in the tank and carb.

Back in the day (circa 1960s) you could buy a product called "Gunk" at the local auto parts store.  The concoction had acid in the solution and came with a basket to put the parts in.  Submerge a carb in that stuff and it came out brand spankin new clean.  Those days are LG (long gone).  Since about 1980 I have not found a single commercial cleaner that would cut the sludge in a carburetor.  Gumout, Gunk, BrakeClean all work equally lousy.  They are very good at killing cockroaches, but they don't work at all on carb sludge.

I asked my buddy Ted what he uses and to my surprise he said "Pine-Sol".  I said no way.  He said way.  He said he uses Pine-Sol.  Said you have to leave the parts in for a day or two but the Pine-Sol eventually softens up the sludge.  He had a Super-E that had been subjected to the classic "sit for 3 years with fuel in it".  It was pretty bad.  No more green goo in this one.  It was 100% black and solid as a rock.  Bowl, intermediate jet, accelerator pump, main jet, and emulsion tube were all completely caked with sludge.  He asked if I wanted to clean it up for him so I said "of course".  Super-Es are my forte.

I regret that I did not take photos of this thing before I cleaned it.  The Pine-Sol ($3.49 at the local store) stinks.  It smells like a hospital room.  This is the stuff our mom's used to clean the bathroom floor.  After a 24 hour soak in the Pine-Sol the sludge was very soft.  All the external deposits cleaned right off with almost no effort.  Running small drill bits through all the teensy-weensy holes removed the majority of the sludge from all the jets, passages, etc.  The sludge built up on the ball checks & spring in the pump assembly rinsed right off with a blast of gumout, as did all the remaining goo in the emulsion tube and jets.  This stuff works really good.  It's not as good as the old-school Gunk from the 60s, but it is very effective at softening the sludge to the point where it is easily scrubbed off or blasted off with Gumout spray.  At $3.49 it's a steal.  Try it, you'll like it (if you can stand the smell.

Several tips.  

Something in the solution sets up an electric couple.  The copper in the brass parts starts to deposit on the aluminum parts.  Best to clean the aluminum and brass in separate containers.

The PineSol leaves a sticky residue on the parts.  I'm sure its fine but I don't like sticky stuff.  A quick wash in warm water with Simple Green removes the residue.

Here's a quick shot of the finished parts.  Like I said, I sure wish I had taken a pic before I started.  I think these parts cleaned up pretty darned good.  If you have a favorite carb cleaner, tell us about it.  Knowledge is power.

Tip for cleaning a clogged pilot jet: hold it with a pair of needle nose pliers and hit it with a propane torch. Just hold the flame on it until one or both openings flare up. Spray a bit of carb cleaner through it to verify the blockage is gone and reinstall. Much safer than running a drill bit through a brass passage and much easier than trying to poke a wire bristle through the stopped opening.

I have the ultrasonic machine from Harbor Freight. A few cycles in Marvel Mystery Oil  does a good job.

The HF ultrasonic machine works great, but comes with a cheap plastic basket. The basket will warp if any harsh chemical is used. Mine distorted after using Gunk carb cleaner in the tub. I paid around $70 for mine but later saw some good looking, all metal construction ones on  E-Bay for the same, or a bit higher cost.