Damage from long soak in Carb Cleaner

[Seakaye12]

Hi....And thanks for the new forum!

I'm working on a Briggs/Walbro carburetor for a neighbor. He had a shop "overhaul" the carb; and...no doubt....it looked "squeaky clean" on the outside......better than new!

However; removing the bowl yielded a fair amount of gritty grey sludge....and the internal body of the carburetor looked and felt rough.

Has this carb been ruined by soaking too long in cleaner?

Thanks, Chuck

[bgsengine]

Hi....And thanks for the new forum!

I'm working on a Briggs/Walbro carburetor for a neighbor. He had a shop "overhaul" the carb; and...no doubt....it looked "squeaky clean" on the outside......better than new!

However; removing the bowl yielded a fair amount of gritty grey sludge....and the internal body of the carburetor looked and felt rough.

Has this carb been ruined by soaking too long in cleaner?

Thanks, Chuck

Maybe.. Maybe not. Try cleaning and flushing it out, inspect rubber parts for damage - was the carburetor installed *SINCE* the shop cleaned / overhauled it?

Gritty Grey Sludge is usually corrosion from water eating away at the aluminum.. But it can also come from the fuel shutoff, fittings, fuel line, etc.

Need more detail on the history since it was "overhauled" - was it then installed to the engine? were the fuel lines and tank flushed out and/or fuel lines replaced? what type of fuel fittings in the line or tank? Using fresh gas with 10% ethanol or less? was gas checked for water contamination?

If you opened the carb up directly after it came from the shop, I would wonder "why" - but even then it would show carelessness (or maybe they gave him the wrong carburetor)

Was the carburetor removed and JUST carb taken to the shop, or was the whole machine taken in?

[wristpin]

Would agree that the type of contamination you describe usually arises from the products of water related corrosion. Some carb cleaning solutions do warn about the possibility of prolonged exposure causing damage to "nylon and rubber" type materials but I've not heard of them attacking alloy components.
I suppose that there is a possibility of re-contamination after ultrasonic cleaning if the carb was not flushed through to remove the last traces of cleaning solution - particularly if a too aggressive solution was used rather than an alloy safe one.

[Seakaye12]

Some more information:

Yes; the entire machine was taken in...about 6 months ago. It has never run correctly...and I was asked to look it over.

I dropped the fuel bowl and noticed that the float wasn't even close to being level with the body of the carb (when inverted). Looks to me like the shop "blew out" the seat with air pressure.....thus preventing the needle from seating properly....thus causing the float to not be level.

So....it was a botched job at the shop on several counts.

It could very well be that there was water corrosion. There was a fair amount of water in the fuel tank.

I guess I'll clean everything up as best as I can and install a new needle/seat...and give it a try..

Any other suggestions?

Chuck

[bobodu]

On the other hand...it may have eaten a protective coating off the metal. I long for the days of the Marvel Scheblers....

[bgsengine]

Float level on a Tecumseh built Carburetor *IS NOT* "Level" - Float level is "slightly down" (when inverted) Bottom of floar (or if plastic float, the "nub") should be 0.173" to 0.185" from the metal gasket flange surface closest to bottom of float. (7/64 drill bit will do) The tecumseh carburetor tool #670377 measures out at 0.173" for float level setting - The OLD style tool (which you would set on top of body where main nozzle threads in - P/N 670253 Its obsolete) is a "Go-No-Go" gauge but only works on brass float carburetors.

Either way, that means float is "not" visually level to the carb body.

If it has never run right, then yes the shop MAY HAVE screwed up - But if there was water in the owner's gas (With ethanol fuel, stored gas will absorb water - which is why EPA Approved containers are needed - vented gas cans will let moisture in the air mix with the gas!)

Then 6 months is more than plenty of time for the carburetor to corrode from water in the gas.

Also an important note: water ABSORBED in the gas will NOT always show up as water in bottom of tank - Phase separation only occurs when absorbed water reaches 0.5% concentration.. But less than that the water can stay suspended in the gas, and mixed with the ethanol, it is still a highly corrosive acid that eats carburetors for breakfast... The end result is that gray gritty debris you find in the float bowl, as well as white "blooms" all over the carburetor where it is exposed to air.

So, after 6 months, there is no way to lay blame at the door of the shop that did the work - It could have been running fine when it went out the door, and then owner fills it up with contaminated gas, the engine no longer runs right..

So.. Make sure the machine runs perfect before handing it to the customer, and then, IN THEIR PRESENCE start it up and demonstrate that it works good.. It's "Covering You A**" - if it comes back not running right again, and corrosion, water, etc are found in the gas, it IS the customer's fault, not the shop's

Other than that all you can do is clean up the carb and see where it goes from there, making sure you drain all the old gas and put in fresh known clean gas.

[Seakaye12]

Hi bgsengine....

It's not a Tecumseh; it's a Briggs/Walbro. Model 498170 or similar carburetor.

And; no...it has never run right since it came back from the shop. Health issues with my neighbor prevented him from returning it to the shop. It's pretty much sat around the whole time.

I'm really not blaming anyone; it is what it is. I do feel fairly certain though that the float level/need&seat issue was the shop's doing...and that's pretty much the root of the poor running ever since.

The float in this carb should be level when inverted; correct?

Thanks, Chuck

[bgsengine]

OK.. Missed that little bit about Briggs/Walbro ... should probably have requested these first off .. But..

Got any engine numbers? Model, spec, and code, so we can look up the specific carburetor you are working with. "498170 or similar" is still pretty vague.. due to the disclaimer "Or Similar" Though, that "should" be an LMS series Also be nice to know what equipment it goes on, which makes for another decent clue to what we may be dealing with.

There's a LOT of Walbro carbs used on Briggs .. LMS, LMT mostly, but they can be quite different..

However, for the most part those are pretty much level floats - especially as they are plastic, non-adjustable type.

With a typical 100000 series Briggs Walbro LMS float carb we pull off a lawnmower.. One of the first things we do when we pop the bowl off is to invert it and see if float is level - If it sits "high" that tells us right away that float needle and seat will be in order (Seat swells from contamination and that low float level - low meaning low when in normal operation orientation - will cause a lean running engine. ). If it sits "low" then likely missing a seat or some float damage (or seat turned to jelly - have heard of it but never seen it) If it sits level, and carb is not leaking gas , it goes straight to the ultrasonic (Along with the float) for a 15 minute run, clean, reinstall needle and seat, with inverted, pressure test to make sure float needle seats, bowl gasket, main nozzle gasket, carb o-ring and good to go. (Float is included in the ultrasonic cleaning for 2 reasons - It does collect gum and varnish scale from the gas, AND heated ultrasonic will prove out the float's ability to , well, float - if float sinks, its obviously no good)

If it is an LMT carb, that's a completely different animal, they have more variations, may or may not have adjustment screws, idle passages, venting, etc.. and there are several different needle and seat kits for those..so engine model , type and code are quite important.

[Seakaye12]

Sure....the code is 123K02-0193-E1...and it's on a Craftsman mower.

My float was "high" when inverted. WAY HIGH. I suspected it was that way because the seat was not "seated" in it's bore....

I have already pulled the seat out; it was in bad shape but I wouldn't say it was swollen. Just kinda dry and miserable looking

I **GREATLY** appreciate all the detail in your correspondence here. It's always a pleasure reading and posting. Thanks!

Chuck

[Skywatcher]

Hi Chuck

I too have run into this situation with the float sitting high when inverted. After questioning the owner, I found out he had been using old ethanol blended fuel which had evidently partially phase separated (ethanol in fuel had pulled moisture from the air and sunk to the bottom of the tank) This ethanol/water mix eats aluminum for breakfast and swells neoprene parts. Replace the seat (follow installation instructions to get seat in correctly) and recheck the float height. Although the seat may not look swolen, it doesn't take much of a difference to upset the float height.

Also, help the owner to understand how gasoline formulations have changed in the last few years, especially with the introduction of ethanol blended gasoline. Now we have to change how we store and handle gasoline so we don't run into these problems. Hope this points you in the right direction. All the best,

Sky