Cleaning Carbs

Discussion in 'Supersport (1974-2007)' started by 749si, Oct 21, 2015.

  1. Hi guys,
    Started the winter strip down of the super light and am at the stage where the engine can now be dropped.
    The carbs are filthy and covered in crap and grit etc, going to send them away to be sonically cleaned but I'd like to give them a good exterior clean first.
    Any ideas on the best thing to use or is it a case of cover them in a mild detergent and get them under a tap with a tooth brush ? Obviously don't want to use anything thats going to affect any seals/ o rings etc.

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  2. Errrr.....CARB CLEANER

    Wynns make good stuff but any will do, its pretty cheap, get a couple cans, it comes out with a degree of force to blast bits off and it makes light work of grime.
     
    • Agree Agree x 1
  3. I would do as you have suggested - any washing up liquid less salt is fine and then carb cleaner but don't let it saturate/remain near seals (but still unlikely any damage will result). The worst risk of the whole job is making sure no grit or foreign bodies enter carb and for this reason I rarely fully strip plus the ultrasonic clean is a bit 'how longs a piece of string' as you can't get behind return springs to remove everything without an (almost) total component strip. I have found a 'let sleeping dogs lie' is the best approach overall with carbs but I understand you want to make things as near new as possible.
     
  4. Hey Chris, how you doing, hope you're well.
    I just want them to look as good as I can get them really, get rid of the grit and shite that's built up over the years, was thinking of using Muc off but that can be a bit harsh and like I said was concerned about any seals etc, they were stripped and synopsis jetted about 5 years ago so I'm loathed to strip them, really just want them looking new...ish
     
  5. Where the hell did synopsis come from !!!! What I meant was Dyno jetted
     
  6. Yeah yeah lol, was gonna use that after I've got rid of the initial thick layer of crap/ grit, if you reckon it'll do the job I'll grab some.
    Once they're clean is it ok to run them under a tap to clean off ?
     
  7. Don't strip the carbs and block off as many 'holes' as possible before you clean the crap off, otherwise some of it might get into pilot circuit and will be a bugger to get out.
     
  8. It's that friggin spell alter checker thingy

    Those are some dirty disgusting carbs there Si tut tut :Finger:
     
  9. I'd agree that if it ain't broke then leave the gubbins alone.
     
  10. Get an ultrasonic cleaner off ebay (they're cheap enough) and some good cleaning fluid, strip them down to component parts and DIY it. I just did my Guzzi carbs and they came out nice.

    That said I'd run those through the wash tank (diesel) first to get the most of the crud off.

    Don't worry about the 'O' rings and gaskets, just replace them.
     
  11. In a bucket with washing up powder. Normally come up like new. Then take them for ultrasonic cleaning.
     
  12. I know viv, they are bad but I don't think that part of the bike has been cleaned in probably 5 odd years, previous owners I might add !!
    Time to get the bike like new
     
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  13. Hey Al,
    Yeah that's what I was looking at doing, don't want to strip them if it's not needed.
    What would you recommend as the best way to block holes, just masking tape or something similar ?
     
  14. Cheaper than Halfords I think!

    Carburettor Cleaner 400ml - Toolstation

    I too would keep it away from prolonged contact with seals and, especially, diaphragms, not because I have had trouble, but just in case. In fact I think I have only used it on my lawnmower so far.

    Toolstation Brake Cleaner is even cheaper. Seems to work fine.
     
  15. No don't use mnasking tape......you will have the same problem if the sticky / glue gets in anywhere........freezer bags cut down to a sensible size and cable ties / wire twists to hold them on over the main inlet and manifold throats.......plug the fuel line hoses with, say, a bit of dowel......leave the bowl overflow hoses on, easy to block them and if you have the larger breather hose stub connections, block them.

    I used white spirit and a 1/2" paintbrush to get the worst off, then Wynns Carb Cleaner and / or brake cleaner to blast some stubborn stuff off.

    But when they are clean I reckon you should at least have the float bowls off...........bound be granular petrol residue in there.

    Also, check the tiny filter in the fuel line inlet T piece.
     
  16. Spot on, thanks Al, I'll post a Pic when they're done.
    Thanks to all
     
  17. The trouble is with the BDST carbs is that the pilot circuit has a blanked off small gallery which you can see when the float bowls are off.........the only way to access it is via the tiny holes and where small jets are installed........cracking a jet can leave a loose residue in the thread, which then gets into the gallery..........all you can do is hope that carb cleaner breaks it down enough to then be blasted out using the carb cleaner force.
     
  18. Removing the float chamber bowl screws can be enough to make a grown man cry. You need a perfect fit screwdriver bit before attempting to loosen them in a conventional manner. If no corrosion is about then this might work on 7 out of 8 screws if you're lucky. If you are not then a sharp tap down on the head can help before applying plenty of downward pressure and clamping a pair of moles on screwdriver shaft for the twisting effort nearly always works as long as the heads aren't damaged already. Trouble is, you're bearing down on the plastic diaphragm covers to carry out above so it's best to remove these just so you don't damage them and then rest on something soft-ish like wood etc. Unless a stickler for originality, now is the time to replace with stainless steel cap Head screws as well. If you decide to remove the little float bowl drain screws be very careful when retightening as the taper seal is so shallow that over 50% of these get cracked by people overtightening as it's so easy to do.
     
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  19. That's brilliant thanks Chris, the two front float bowl screws are looking pretty rusty so think I'll leave them for another time, or I might just have a moment at three AM, anyway back to the carbs
     
  20. It's a good idea to give those float bowl cap screws a good soaking in penetrating oil before cracking them.......One of mine brought the thread out of the carb body with it....

    .....resolved it with a 6mm tap and cap screw.
     
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