Mazda Rotary Club

General => Rotary and General Chit-Chat => Topic started by: Jamie R on April 26, 2023, 01:21:22 PM

Title: Carb cleaning
Post by: Jamie R on April 26, 2023, 01:21:22 PM
Hi Guys,

I have a crusty old carb (Nikki from 12a) that ideally needs pulling apart, servicing, ultra sonic clean the internals or replace parts.

Can anyone recommend in the UK a company that provides this service or is an expert outside of the usual guys that just seem to work on DCOE's these days??

Or does anyone on here have the capabilties???

£££ available.

Thanks

J


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Title: Re: Carb cleaning
Post by: Casey on April 26, 2023, 08:38:33 PM
I'm not aware of anyone offering this service, but there must be someone out there.

I have dismantled one and ultrasonically cleaned all the parts. I have a rebuild kit to use on the rebuild, but haven't started that yet. I just hope I've taken enough pictures during the disassembly to put it back together correctly. It's a time consuming and fiddly job and I'm not confident to do another one until I have this one back together and running.
Title: Re: Carb cleaning
Post by: clive on April 27, 2023, 08:36:17 AM
You should be OK doing this yourself.
If not contact  https://www.southerncarbs.co.uk/contactus_53351.html
Title: Re: Carb cleaning
Post by: jinx on April 27, 2023, 09:28:00 PM
Southern Carburettors are a fine body of men and undoubtedly very useful... but do check the contents if a 'kit' is what you buy from them. It is not entirely impossible that the "Full rebuild kit' could more properly have been described as a 'full kit of the bits we stock'.

I have been (mildly) disappointed in the past but maybe I had unrealistic expectations. :(
Title: Re: Carb cleaning
Post by: Jamie R on April 27, 2023, 09:38:44 PM
Quote from: jinx on April 27, 2023, 09:28:00 PMSouthern Carburettors are a fine body of men and undoubtedly very useful... but do check the contents if a 'kit' is what you buy from them. It is not entirely impossible that the "Full rebuild kit' could more properly have been described as a 'full kit of the bits we stock'.

I have been (mildly) disappointed in the past but maybe I had unrealistic expectations. :(
That's a fair point mate


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Title: Re: Carb cleaning
Post by: Jamie R on April 27, 2023, 09:41:52 PM
Well I have been blessed by knowing a very kind gentleman who is brave enough to share his equal amount of logic, methodological nature and skill, we are going to tackle it together!

Should have a few giggles too


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Title: Re: Carb cleaning
Post by: DaveCollins on April 27, 2023, 11:13:45 PM
I would certainly recommend this as a great resource for describing how to tackle rebuild.  There appear to be a fair few small variations on throttle linkage depending whether carb is from Left/Right hand drive car and if it has US smog controls built in.

Mazda Carb rebuild manual (https://foxed.ca/rx7manual/manuals/mazda%20carburetor%20manual%201979-1985.pdf)

I was able to rebuild the carb on my 1985 spec 12A.  Be careful with what rebuild kit you buy (Rock Auto has them) to ensure that you get the one with the correct air horn gasket for your model of carb.  I used the Walker Products one

Walker products Nikki kit (https://www.rockauto.com/en/moreinfo.php?pk=11059856&cc=1192294&pt=5964&jsn=816)

Biggest bit of advice is not to change the fuel inlet needle valves unless you absolutely have to as resetting float height was the trickiest and most time consuming part of the job. Using the standard Mazda measurements did not give consistent fuel levels and I had to adjust each one a small bit at a time before it was correct.

Dave
Title: Re: Carb cleaning
Post by: Jamie R on April 28, 2023, 03:57:01 AM
Thank you kindly Dave


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Title: Re: Carb cleaning
Post by: Casey on April 28, 2023, 02:26:38 PM
The layout of this doc leaves a bit to be desired, but looks worth reading as it contains some practical advice, based on someone who has been there and done it a few times!

Rebuilding the Nikki Carburetor 4.doc
Title: Re: Carb cleaning
Post by: Jamie R on May 05, 2023, 04:54:25 PM
Quote from: Casey on April 28, 2023, 02:26:38 PMThe layout of this doc leaves a bit to be desired, but looks worth reading as it contains some practical advice, based on someone who has been there and done it a few times!

Rebuilding the Nikki Carburetor 4.doc

I trust youve memorised in readiness for our bash ole bean ?!?!?!
Title: Re: Carb cleaning
Post by: Eccentric shaft on May 05, 2023, 05:52:46 PM
So many versions, mods old and new
No-one has a clue about what jet and screw
They called her Nikki
And she's mighty tricky
No wonder that you need a brew!


(Sorry! I got stuck in limREick mode!)
Title: Re: Carb cleaning
Post by: Casey on May 05, 2023, 06:56:05 PM
Quote from: Jamie R on May 05, 2023, 04:54:25 PM
Quote from: Casey on April 28, 2023, 02:26:38 PMThe layout of this doc leaves a bit to be desired, but looks worth reading as it contains some practical advice, based on someone who has been there and done it a few times!

Rebuilding the Nikki Carburetor 4.doc

I trust youve memorised in readiness for our bash ole bean ?!?!?!


 :))  :))  :)) With luck, I'll have a chance for a quick browse before your arrival  ;)
Title: Re: Carb cleaning
Post by: Casey on May 05, 2023, 06:56:30 PM
Quote from: Eccentric shaft on May 05, 2023, 05:52:46 PMSo many versions, mods old and new
No-one has a clue about what jet and screw
They called her Nikki
And she's mighty tricky
No wonder that you need a brew!


(Sorry! I got stuck in limREick mode!)

Sums it it quite well I think!
Title: Re: Carb cleaning
Post by: Jamie R on May 20, 2023, 10:52:30 AM
(https://uploads.tapatalk-cdn.com/20230520/a6e1dd6503cd757483d3e4338ab4dba2.jpg)

The brummie invaded Essex for a day of carburettor surgery


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Title: Re: Carb cleaning
Post by: Eccentric shaft on May 20, 2023, 04:59:29 PM
Nice portrait of the Surgery Daddys   ;) 
Title: Re: Carb cleaning
Post by: Jamie R on May 21, 2023, 05:24:26 AM
Quote from: Eccentric shaft on May 20, 2023, 04:59:29 PMNice portrait of the Surgery Daddys   ;)
The guy is a legend Yngvar. Would not have done this without him. Thankfully he's done this before.

We had a good weekend. Very productive with a few giggles..... oh and "double entendres "( remember it's  got 1 big hole and 2 smaller ones Malcolm) haha
His wife Gwyn is lovely !
Superb hospitality
Amazing food
Lovely place
Gorgeous weather.
Oh and if ever you drop a 2mm ball bearing outside in the wind. This guy will find it lolll

Malcom, Gwyn  thank you

P.s Don't think I've gone this long without swearing. I'm gonna have Tourette's in the car on the way home.

And I've never seen you as speechless as when I showed you that painting !!! Lollllll


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Title: Re: Carb cleaning
Post by: Casey on May 21, 2023, 11:14:14 AM
;D  ;D

Thank you Jamie. It was a pleasure to share a very enjoyable day with you on a task involving our shared passion of cars.

I had my heart in my mouth when that 2mm ball-bearing went flying. I was so relieved to spot it so quickly on the patio!

Thank you for your excellent company, for your self-control  ;) , your generosity with the pub dinner and the flowers, which Gwyn loved.

I hope the carb works as it should - at least we can be sure everything has been checked and cleaned!

As for that painting, words just fail me  :D

Looking forward to seeing you again soon ( with the Rotus  :notworthy:)  at Combe  :13:
Title: Re: Carb cleaning
Post by: Casey on May 21, 2023, 11:19:12 AM
Oh, and post up a pic of the carb when you've added the plated bracketry  :)
Title: Re: Carb cleaning
Post by: Jamie R on May 21, 2023, 01:14:20 PM
Will do


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Title: Re: Carb cleaning
Post by: Casey on May 23, 2023, 04:24:40 PM
For anyone contemplating this task, here's a helpful video. Jamie and I should have watched this first, but it seems we pretty much followed this process anyway. In fact, we went a stage further by removing, cleaning and re-assembling the primary butterfly actuating mechanism.

Several things to note:

There are 2 tiny accelerator pump weights that sit above the check-balls. One looked very different we had. I loved it (at 30m28s in, where Charles couldn't find one of the check-balls  ;D )

The gasket differences! Charles showed yet another (1 or 2) variant(s) of the gasket above the throttle body.





@Jamie

@33m, Charles describes the 2 different accelerator pump diaphragms that came with the re-build kit(s), and the positioning of the spring too.

@37m25s Interesting bench test of the accelerator pump.

@46m05s Charles doesn't put in the pair of fine mesh fuel filters? Surprising, and he doesn't say why - apart from the fact the carb he's working on must have had them removed on a previous rebuild.

@51m45s Ah! The two O-rings in the kit are, apparently, new seals that go behind the fuel bowl sight windows! The ones we took off looked OK though.

@52m40s Charles shows the two types of main gasket that we were puzzling over.



Also some good setup/troubleshooting stuff here, from the same guy: