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Collection, Preservation and Display of Old Lawn Mowers

What to use in ultrasonic bath?

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Once again, showing my ignorance. Don''t worry, we won't run out, I have an endless supply! I have the loan of an ultrasonic cleaner with which I intend to clean up the carb on my Atco Standard - it's distinctly grubby and has rust in the bottom of the float bowl which I'm sure can't help it run.

Firstly, what should I use as my cleaning solution? I see that  I can buy various commercial concentrates, though that may be overkill for one simple carb, plus either keeping or disposing of several litres of made-up cleaning fluid. Presumably if I use a detergent solution I have to be very careful to make sure that everything is genuinely dry, or I'll be cleaning the rust off again straight away.

Next, how far down should I strip it? Certainly take the bowl off, do I need to remove the needles and the compensating tube in the carb throat? Is it worth doing the fuel pipe as well (this has a braided outer no idea what the inner is)?

Sorry for all the questions!

Adrian

Forums

Ransomes-Suffolk Sat, 06/06/2020

I raised a similar question the other week (www.oldlawnmowerclub.co.uk/forum/history-and-technical/technical/ultras…). The Youtube video recommended to me is very informative and answers our question. 

I would be inclined to strip a carburettor as much as possible prior to ultrasonic cleaning to allow the cleaning fluid good access to all parts and increase the chances of dirt and debris which the ultrasonic action removes being carried well away into the cleaning solution i.e. if the item is largely intact, there is a chance that insoluble dirt removed will float a small distance through the carburettor and end up being deposited elsewhere when lifted from the bath which could then potentially cause a blockage somewhere negating the benefit of cleaning.

wristpin Sat, 06/06/2020

Good advice above. I would add  turning the carb during the cleaning cycle  so that the dirt can drop out .  I use a proprietary cleaning concentrate and filter and save the dilute solution  for reuse a couple of times.  

Adrian Sat, 06/06/2020

Thank you, gentlemen, looks like carb cleaner it is, and strip as far as I can sensibly go. I wonder while I have the thing whether it's big enough to clean the fuel tank too... probably not, it's a bit of a biffa, but maybe not quite that big. 

Anyone else find they have a tank, and immediately start looking for things to zap in it? I think my fuel cap with the "16 parts" inscription might be the first in...

Adrian Sun, 07/06/2020

Nope, tank is approx 13", bath approx 11". Ah well.

Tank cap will need carb cleaner, but a bit of Fairy works a treat on cruddy bits of metal off the allotment. Mind you, it doesn't half smell - I'm assuming that that's what happens when a tank that's been used to clean revolting lab equipment for a couple of decades warms up.

RedLeader Mon, 08/06/2020

I've recently ventured into the world of Ultrasonic cleaning - mainly to clean my carb, but finding all sorts of things to clean now! My tank came with some proprietary carb cleaner which has a recommendation of 1:10 mix with water. Done a great job of cleaning up my Zenith carb, but I've also used fairly liquid and water to very good effect on other things. The heating function also aids in the removal of some of the grime too.

Adrian Sun, 21/06/2020

Well, the bath is currently buzzing away in the bikeshed with my largely dismantled carb sat in it (I drew the line at undoing the tickler as I've nothing fine enough to redo the little brass split pin).

I thought I'd share these findings with you, once I'd strongarmed the fuel pipe off I found the little inline filter below was looking in need of TLC - no wonder the poor thing was popping and banging! Looking at it, I'm seriously thinking about filling my fuel tank with cleaner and doing first one end then the other.

Something I've also known about for years is that the carb seems to have been brutalised to fit a slightly smaller stub than intended - I'm wondering whether it would affect the engine's breathing if I were to open the ends with a screwdriver and shim it for a tighter fit (was drinking beer from a can only last night) - and whether I'd need a new, straight, bolt too!

Your thoughts woud be welcome - engines are not really my thing and as I'm sure you've realised I'm working it out as I muddle along!

 

Adrian

PS Looking at villiers carbs on ebay - someone is selling a carb float for a Wall Autowheel - there's a machine I'd like to have! and, even stranger, it's handmade in Poland! I  cannot imagine Poland is a hotbed of Wall Autowheels, can you?

 

Adrian Sun, 21/06/2020

High excitement! I have an extra bit! One more part came out than went in! It's a soft washer - from the size I think it must sit under the brass centre piece but, as it's almost exactly the same colour, I just didn't spot it when  dismantled.

I stopped it a few times and moved things round, and got a toothbrush into the crevices, and it looks very good. The air cleaner is cleaner than it's been for decades - even when I got the mower 30-odd years ago, it was pretty gunged up - and it's taken all the green-blue corrosion off the brass fuel caps too.

Of course, it might not work any better (I did also get new fibre washers from Evotek Marine who, as the name suggests, mostly cater for Seagull outboards), but it'll look good.