Dont bother with the vinegar!

[richard]

in my last post i did say i was FRIENDLY . but bob !! any talk of a communal bath is far too early . i feel i hardly know you 

[Chris Thomas]

Dear Bob

I am told by somebody who renovates Aston Martins that the outside of zinc based charburetors should be bead blasted with either crushed almond shells or plastic beads to remove the resin deposits on the surface. Soda ash blasting or Cyrogenic cleaning with carbon dioxide are other option but they are expensive.

The inside should be cleaned with coastic soda to clean out the resin deposits from the internal bits. Like acid it will disolve the zinc away if you use it too strong, hot and for too long. You need gloves and a respirator so be careful. Small items like jets can be cleaned in an ultrasonic cleaner. I recently bought a small one in Aldi for £14 like you see on ebay for £30. But they are not big enough to get a complete cerb in them.

We can blame the good old EEC for all the proprietry cleaners for not working as most of the chemicals that were in the old products are now banned.

I hope that this information has been of assistance

Chris Thomas

[Bob Purton]

Richard, I thought having had the shared experience of the gruelling journey to Story together would qualify me as a close friend!? After all I know secrets about you, for instance the fact that your cooling shroud exploded all over the M25! The fact that you arrive for the ferry just as the gang plank is going up! Not to mention the eating of biccies on the autobarn! Bringing the convoy to a stand still after catching your blinker switch in a jammy dodger etc! What a shame we cant do it all over again! But on reflection, I still wouldn't want to share a bath with you!

Chris. Thanks for the research. I have heard of the blast cleaning of the outside of carbs before, its something the concourse boys like to do and why not. The thought did cross my mind that caustic would remove the gum but I thought it would be more destructive than vinegar acid. Years ago I left a compass in a bucket of caustic over night to remove the paint, when I took it out the next day half the parts were missing! I didn't realise that some of the parts were made of aluminium and they had completely disolved away! I think it would be a good idea to boil up the brass jets in caustic but I wouldn't put an alloy carb body anywhere near caustic myself unless they mean targeting small areas like passage ways with it for a short time. I guess one could use a syringe making sure it doesnt get on important surfaces like the slide throat and other parts where a tolerance is crucial. I can understand why your sonic cleaner is not big enough to take a cerb, especially granite one? Ho Ho 

[g-o-g-g-o]

Hi Bob
          I have cleaned a carb that was soaked in vinegar, and it etched the outside of the carb - that was no problem to me - but it did destroy the steel parts of the carb like the needle and the accelerator pump spring, I tried for 2 hours to get the destroyed spring out of the brass tube but I had to give up and place a new accelerator pump tube together with a new needle, you are right the deposits in the jets vinegar did not clean.
   When I am cleaning a carb I strip it all down then wash all of the parts in petrol and then use an air line to blow all of the deposits away - Most carbs have anodised outsides so it's no use cleaning them, the inside parts like the piston- I wash them with petrol and then polish them ( usually with solvol autosol ) clean them again to wash the cleaner off and then reassemble the carb - and it's like a new carb.
   I feel you are using the cheap option rather than doing a proper job on the carb.

 I am an engineer so I do the job properly - and it is usually quicker than your "Quick Options"

[Bob Purton]

Hi .  We would be a bit worried and surprised if you didn't do the job properly Mike! My original reason for starting the thread was to find out if anyone has found something that will dissolve stale fuel gum, the sort of stuff deposited in a carb when left with petrol in it for about ten or twenty years. We all start by flushing with petrol and blowing through with air but as you confirmed, this doesn't shift the gum.  Can you as an engineer recommend something that will do this? I know you can poke something through them like I did or is that what you do too? [ I have ordered a new jet to be on the safe side]  The fact is Mike, I dont have a method be it quick or slow and am just trying out thing people suggest in the hope of learning something. For instance you mentioned polishing the piston slide, that's something I haven't tried before, whats the reasoning behind it or is that a trade secret?

[g-o-g-g-o]

Hi Bob
          It's no trade secret it's just to make the piston more slippery and speed up the acceleration by a fraction of a second - I too have a set of tools to gently clean out the brass jets.
                                                                                                                                                                           Mike

[Bob Purton]

Ah, that makes sense Mike because you tend to get those tram lines wear marks in the piston. I have noticed though that it doesnt happen so much with two strokes, I guess its because of the oil in the petrol continually lubricating the slide. I shall go polish my slide tonight and see if my Guzzi goes faster!

[jackiep]

Hi Bob & All ,
  The Caustic Soda sounds TOTALLY lethal , logic says if it needs a respirator & thick gloves , its not a job for the amateur no matter how good they are ( engineers excepted naturally ) .Certainly when Dad was replacing a clutch it fell to me to clean out the housing , first with Jizer using a smallish brush if needed  & then washed off with water ,  wiped off  carefully with with a rag -- just to get the worst off & then blown dry with the air line .Its amazing how much muck comes off .
               Is the sonic cleaner the same liquid used in sonic glasses cleaner? They are quite cheap & I 've got one if anyone wants it .I've no idea whats in the solution , but it does not damage  the  optical glass .
              I could not think of attempting cleaning something without considering the consequences of damage to the item .  Just not worth the risk .. Pay the expert !
                 Belated Happy Bubbling New Year All ... Jackie

[Big Al]

Sonic cleaning is tops but if the jet is not demountable the bath size is an issue and the carb needs to go in. Cost against jobs but good tools are an investment.
The other methods are all a problem for one or other reasons. Caustic soda loves to dissolve aluminium and to a lesser extent brass. Great for clearing out radiators but you risk a leak. Jets, slides etc. have to be the correct size to be spot on designed performance. Thus polishing them is imperfect as you are increase the area of the hole just as a corrosive agent will. A solution to clean is therefore the next best answer but I do not know what it is. Polishing works but then the unit might be compromised. A favourite is worn Bing slides. They are not sealed from air and the increase of gap means the thing can move, wobble and set off an accelerator jet giving inconstant tick over and leak air into the mixture meaning perfect tuning can never be found. If money was no object the carb could be sleeved to stop this but to be honest a different carb is a cheaper and better option often as the Bing is pretty crap.
Of course often a different carb is not so obvious so the issue remains what is the best solvent to use to get the jets cleaned up. Till I know I will stick to immersion in diesel first as it softens and penetrates much of the muck. An airline fed with water, modified airgun, sort of amateur vapour clean works but some areas can be hard to get at and it is dangerous for eyes and digits as the water can create an embolism through the skin. Shiny carbs, well shiny does not mean working so I leave that to those who have that desire. I prefer a sheen of oil as it means no corrosion.

[Bob Purton]

I think this thread has been more or less exhausted now and the conclusions I have come to are much the same as what Al just said. Sonic baths appear to work, solvents on the market do not. Soaking in Vinegar or caustic more than likeley will erode the surfaces, best way to clear a jet if you have no access to a bath is poke something through it that is softer then the brass jet. Also learned that everyone has there own methods including polishing the slide which some are against because it is removing material from it, others like Mike recommend it and reports no ill effect, I guess because the amount removed is miniscule and you dont do it very often, besides you can always buy a new slide for most carbs. Hhhhm, interesting tread but still have not found the magic solvent!   Lets move on to another topic.

[AndrewG]

 Lets move on to another topic.

Do we have to? - I was assuming the Finbar Saunders-esque discussion of communal sonic baths and polishing one's own slide was going to degenerate this topic into some really amusing filth.

Fnarr, fnarr.

[richard]

funny enough it did !  so much so i sent it by personal message to bob rather than the forum 

[Basket case]

I'm new to all this so I fear that you cynical Pro's may shoot me down in flames.

I use cellulose thinners (soak for a couple of days and then clean with a toothbrush), followed by compressed air.

Machine Mart also do an alloy cleaner but it contains potassium acid and is quite harsh, so  that is my last resort for really stubborn gum

[Rob Dobie]

I use cellulose thinners.

As Billy Bunter always exclaimed, "Crickey". ...... I remember using to use this in the middle 1960s when I had motorcycles and my first car. It certainly did clear all the glazing in the carbs.

Last year I got rid of my heated ultrasonic cleaner, 2.5 ltr tank, as I haven't any vehicles anymore. It used Sea Clean Concentrate (seaweed, coconut oil & fruit extracts) mixed with warm water. It even helped clean off rust.

[Chris Thomas]

Dear Bob

I have just seen on the interweb that on 13 Jan 2011 my favorite shop (ALDI) will be selling as a special offer item a 750ml Ultrasonic cleaner for £19.99. If you have not got one then now is your opportunity. These offers tend to repeat on an annual basis so you may have to wait a long time for the next special offer.

There are 4 stores within 5 miles of you so if one sells out you have a fair chance of still getting one.

Chris Thomas