small carb cleaning, show-n-tell

[Quest]

I just received another request for fixing B&S 6.25 sidedraft carburettor over this weekend, so I decided to do a show-n-tell to share with you folks:

This is how the Walbro LMS carb (clone, chinese stuff) looks like before the restoration begins:



As my Branson 3L ultrasonic cleaning machine is out of commission, I'd had no choice but resort to the measure of using my rather low-powered, jewellery cleaning one (approx. 0.75L):



3 rounds of cleaning with water and a few drops of dawn clean things up nicely:

(picture after 2nd round):



These are the pics of the end result after 3 rounds of cleaning (total time around 15 mins):





Beast of all: ultrasonic cleaning will break down/disperse any debris into very fine dirt, including those that may have clogged your otherwise very find jets and passageways. Patience is key, esp. when using low-powered ultrasonic cleaning machine. Give yourself sufficient amount of time and keep changing out the filthy water with fresh new one until the water is clear (that's the last pass).

With a fresh new gasket kit, the carb is now running fine on the B&S mower.

Q.

 

[Quest]

sorry for the typo folks, I need new glasses.

 

[oilboy123]

Other than the grass/dirt on the outside, that carb looks immaculate. You should see the salted ones on the outboards at work. They sometimes have corrosion inside the float bowl.

Nice pics and explaining of the process.
I have wondered about using a smaller ultrasonic machine. I see harbor freight sells a couple of units. I might get one someday.

 

[Quest]

experiences told me that those (carbs) that have experienced heavy corrosion (salt water, such a marine outboard), or gas-water induced corrosion, etc. cannot be restored satisfactorily, regardless of how "aggressive" your attempt is.

Even when using high-powered ultrasonic cleaning machine, those carbs cannot be properly restored, period.

This LMS clone has some minor high-speed issues (typically leading to hard starts when engine is hot), but otherwise in ok condition.

There's no idling speed/mixture to adjust, so you are pretty much stuck with what you can do with it, short of replacing it with a fresh new aftermarket replacement.

3 pass through the ultrasonic cleaner, a new carb gasket kit + some compressed air pretty much restored it 100%.

As soon as I received my EX1000 generator service manual (something to reference against), I'm gonna run that carb through my ultrasonic cleaner as well...

Q.

p.s. the pic where the carb in the ultrasonic cleaner tank is, in fact, the last pass...first 2 pass the water was gunky and was dumped immediately and the tank was quickly rinsed off before filling for the next pass.

 

[Bluestream]

I have always used a brush and some carb cleaner spray with compressed air. Works great and fast

 

[Merkava_4]

Hopefully, you won't have to pull that welch plug that's next to the float hanger.

 

[Crashbox]

I like this idea. Asking it to remove fuel varnish would probably be a bit much, though... and I definitely do NOT want to use something hazardous in my US cleaner.

For the record, I have a small half-gallon and a 3.25-gallon commercial-grade (Crest®) ultrasonic cleaners; if the small one is too small the larger one can handle it. A good investment in my opinion.

 

[jhellwig]

How would simple green or that purple power stuff do in there?

It looks like most of that dirt would have brushed or blown off. Where is the caked on oile dust?

 

[Merkava_4]

Originally Posted By: jhellwig
How would simple green or that purple power stuff do in there?


It will eat up your carb if you do any soaking with it. That stuff is spray on/rinse off.

 

[Quest]

strong alkali (or caustic) solution and pot metal (alu alloy) are not friends. IT will eat or corrode the pot metal.

Things like Castrol superclean, etc. are caustic (strong alkali)

Q.

 

[jhellwig]

Hrm. I didn't know that.