My Carb Cleaning system

Correctly servicing the Carburettors on these bikes is paramount to good running and fuel economy so any work done will pay back in better mileage :)
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My Carb Cleaning system

Postby Gman » Sun Sep 07, 2008 1:28 am

Warning!If you have the Accelerator pump/Vacuum type Petcock type Carbs do NOT soak in Vinegar as it will melt them.Only do the carb bodies and NEVER boil the carbs,just cold soak.


My carb cleaning system differs from LRCXed(which is excellent) inasmuch as it's not as intensive but no less effective.Check out his Sticky in this section as well as a cross reference,
http://globalcxglvtwins.hostingdelivered.com/viewtopic.php?f=19&t=32

Note:I NEVER split the carbs unless there is a leak from the Transfer tube as they can be a PITA to get back together.

If you have not done this before make sure download and or buy a manual but it can be done with the information on here.

Tip1::Use your Cell/Mobile phone/Digital camera to take pictures of the cable setup before you remove them from the carbs if you have one of these if you are unsure of things.This will help when re-fitting the carbs and also before you strip each part of the carbs again if you are unsure.

Tip:2 I keep and clean out plastic margarine tubs to use as containers for parts when stripping things off my bikes.

Preparation:
Buy a couple of bottles of white Vinegar from the supermarket and a can of Carb/Brake cleaner from Autozone type shop.I'm assuming you have the tools to remove the carbs etc.


More info,

http://www.pdsrecording.site90.com/cxgl ... bMain.html


1:Before removing the carbs place a container under the overflow pipes underneath at the back wheel.Slack off the bleed screw on the left hand side float bowl bottom and wait.Takes about a minute for all the petrol/gas to drain.
Remove the Idle screws but taking care that that they have a small spring/washer and very very small o-ring on each of them.






2:Remove carbs and A pull cable(Has two lock nuts) and the B push cable(Only has one lock nut) and the choke cable.Try and remember where they go or as above a take a picture.
3:Remove float bowls(If possible go and get some Allen screws and replace at least the inner hard-to-get-to screw on the floats bowls for later.You will see why later)

4:Remove float pins and floats and FNV(Float Needle Valve) and place into containers.

Check the very tiny plungers in the top of the Float Needle Valves have not seized.They are spring loaded.

5:Remove jets.
Note:The standard jets on these bikes are 78 and 112 punched into the sides of the jets.The 78 always goes straight into the carb body.The 112 always goes into it's Brass Emulsion tube holder in the centre of the carb.Try and remove this one from it's holder and the holder from the carbs so they are separate.

6:Remove the tops of the carbs taking care with the slide springs when you remove the slides and note the Black nylon sealing ring whose lip ALWAYS goes upwards

7:Remove the Black Banana that is the idle circuit cover.

8:Check the condition of the Air-cut-off assembly especially for small holes in the diaphragms.

Servicing.

Half fill an egg cup with White Vinegar.Drop all the jets and the emulsion tubes in it and leave to soak for at least a couple of hours better still overnight.

Get an old pan or similar container and put one side of the carbs into it(Still connected to each other) and then fill up with enough white vinegar to cover the whole of that side's body and again leave to soak preferably overnight.
Then flush this side out under the tap with clean water to neutralize the Vinegar(Acetic Acid)
Then turn it over and do the other side and flush it out with water after a long soaking.The white Vinegar being a mild acid(Acetic acid) will break down the fuel Patina(http://en.wikipedia.org/wiki/Patina ) and oxides etc that can coat the insides of all the venturi/fuel/air pathways that can even be invisible to the naked eye.

Take the emulsion tubes out of the egg cup and I use a needle or pin to make sure all it's side holes are clear and then give it a light clean with some soft scotchbrite/fine pan scrub.

Then check the jets and if you want to poke them through I NEVER use anything metal as the jets are made of very soft brass and can be easily damaged.I use either a bit of nylon fishing line or a nylon bristle off a cheap hand brush I have.

When you are satisfied that all parts have soaked enough I blow all the parts and then the carb bodies an ALL the holes through with the Carb/Brake cleaner.I give then a real good soaking/blow through as we want then right.

Now and probably the most important part and should not be skipped.The jets/Emulsion tubes and Carb(All holes and pathways) MUST be high pressure air blown through.If you don't have a compressor of you own take them down to a local garage and ask if you can borrow their high pressure airline with narrow blower.A lot of times if you are polite one of the guys will do them for you as a favour especially if you explain what they are off and how old the bikes are.

Check the slides for scores and see if they move ok in the bodies.If need be polish with metal polish and clean off with Carb cleaner.Re-build the carb tops 1st remembering the above black seal ring lip goes upwards.



Before you re-install the bottom parts check the tip off the FNVs(Float Needle Valves) and if damaged badly will need replacing(Carb service kits are available see links section).If they seem ok you can actually re-grind them a little like you would with normal Head valves using a bit of metal polish or Toothpaste which is a fine abrasive and placing them into their holes and spinning them gently and the flushing again with Brake cleaner after done.

Also check the Idle adjuster holes and make sure that the small o-ring that sits on the screws when they go in has not got lodged in there or an old perished one is causing a blockage as this has been known to happen.

Re-fit them and the floats and also read here on setting the correct float heights,
http://globalcxglvtwins.hostingdelivered.com/viewtopic.php?f=19&t=110

Before re-fitting the carbs check the carb boots for splits and repair or replace in necessary.You can check they have no leaks by placing one end on your hand(Wet your hand if need be) and the other on your mouth and sucking to make a vacuum but make sure you have cleaned them 1st otherwise they taste nasty<grin> :twisted:

When re-fitting make sure that the boot's lips that go onto the carbs are seated correctly and not at an angle.When you put the carb into the bike always fit the boots to the carbs 1st and make sure they are absolutely correct and tighten them up.Then you can place the bolts on the engine side in and tighten them.Do NOT do tighten them at the engine side 1st as this cab pull them away just enough from the carbs to cause air-leaks and thus weak mixture/high idling.

When you re-fit the Idle screw adjusters make sure they have the spring ->washer -> o-ring on them and you do not crush the small o-ring inside the body or that an old one may have got jammed in there.

Addendum:I now use a Guitar string anyone from 0.014" to 0.30" and poke it down the four slow speed holes in the top of the carbs including the 2 under them"Black Banana" and really blast these out under the sink tap/fawcett and with compressed air.You can also blast some WD40 down them and leave for a while and it will break down the oxide formation in the venturi.
I NEVER use anything metal to poke through actual jets as it can damage the soft brass.This is not the same as carefully using say a needle through the side holes of an emulsion tube if you have removed them from the Carbs.These are not as critical and can be cleaned carefully or boiled as per above.




HTH :P
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Gman
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Re: My Carb Cleaning system

Postby spanish bandit » Wed Sep 02, 2009 3:11 pm

hi shep.my new[ha ha] 20 pound carbs turned up,so im preparing to service them.on reading your cleaning method,10 times :shock: i see no mention of acv,s.is there a reason that they arnt mentioned.
cheers :Dfrom the pain in spain :oops:
uk 1982 gli silverwing
uk,1981 gl troublemaker

when i feel the need,i do it
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Re: My Carb Cleaning system

Postby Gman » Wed Sep 02, 2009 4:15 pm

spanish bandit wrote:hi shep.my new[ha ha] 20 pound carbs turned up,so im preparing to service them.on reading your cleaning method,10 times :shock: i see no mention of acv,s.is there a reason that they arnt mentioned.
cheers :Dfrom the pain in spain :oops:


There's not a lot to them.If they are perforated you can bypass them.If not just take them out and clean all the holes.Don't lose the tiny O-ring(flat face towards you).When I get round to it I'll put a full web page up again.I've even bodged perforated ones using some spray impact adhesive I have.Even petrol won't dissolve the stuff,

http://cgi.ebay.co.uk/Servisol-Spray-Glue-Adhesive-120_W0QQitemZ140338139645QQcmdZViewItem
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Gman
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Posts: 1141
Joined: Thu Jul 24, 2008 8:11 pm
Location: Hull.Yorkshire.UK.2x1980 CX500ZABs:Citroen ZX TD(250,000 miles)

Re: My Carb Cleaning system

Postby spanish bandit » Thu Sep 03, 2009 8:38 am

Sheppola wrote:
spanish bandit wrote:hi shep.my new[ha ha] 20 pound carbs turned up,so im preparing to service them.on reading your cleaning method,10 times :shock: i see no mention of acv,s.is there a reason that they arnt mentioned.
cheers :Dfrom the pain in spain :oops:


There's not a lot to them.If they are perforated you can bypass them.If not just take them out and clean all the holes.Don't lose the tiny O-ring(flat face towards you).When I get round to it I'll put a full web page up again.I've even bodged perforated ones using some spray impact adhesive I have.Even petrol won't dissolve the stuff,

http://cgi.ebay.co.uk/Servisol-Spray-Glue-Adhesive-120_W0QQitemZ140338139645QQcmdZViewItem

thanks shep,ill look foward to reading the full web page.
i spent an hour on cleaning the outsides of the carbs yesterday,they were bad.
coated liberally in hilti penetrating fluid,and put in a bag overnight.well,looked at them closely this morning,and wow :) the boots are brand new,they are worth more than 20 quid each.so, im chuffed. :D
i know you said they are a pita when seperated,but im still debating.......i have time on my hands and id really love to polish and clean them up nice....
uk 1982 gli silverwing
uk,1981 gl troublemaker

when i feel the need,i do it
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Location: southern spain

Re: My Carb Cleaning system

Postby Boomi » Wed Jun 23, 2010 11:52 am

Thats awesome..:D
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