Author Topic: Carb to Air Box Connection  (Read 3580 times)

Offline mrduc1198

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Carb to Air Box Connection
« on: 30.05. 2012 11:38 »
Hi Guys:

I've seen this topic on the site and have read through them(and pictures) but didn't quite find the answer I was looking for.

The motorcycle is FRAME:    ZA7R/1824 and ENGINE:    ZA7/3861.  The Carb looks to be a 1947-48 identified as  276 CY/1A.

My basic question is how is the carb meant to connect to the air box?  When I got the the bike it had electrical tape wound between the two.

The carb has a threaded end which looks like it will take bellmouth fitting.  Would that then go flush against the air box (or close to it)?

Or is there meant to be a rubber bit that makes an air tight connection from the carb to air box? This is what I seen in my manual but it doesn't look like it would fit properly.

This is all a bit of mystery which indeed makes it fun and frustrating.

Any words of wisdom appreciated.

thanks

Online bikerjohndavies

  • John Davies, Bath, UK
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Re: Carb to Air Box Connection
« Reply #1 on: 30.05. 2012 12:02 »
Hi, There is a rubber that fits from the carb to the airbox. I got mine from a chap in the UK called Jeff Hunter. He makes all three types.  Mark 1 A7 longstroke, mark 2 A7 and A10 plunger. He does take a little while to respond but he is reliable and the rubbers are good quality.

Jeffalanhunter@aol.com

Out of interest I have just finished my 49 rigid A7 and mine has the frame before yours. ZA7R 1823.

Cheers, John
1931 Ariel VB31, 1935 Triumph 5/3 project, 1946 Ariel Square 4, 1952 Norton Model 7, 1953 BSA A10 Super Flash, 1954 Ariel VH

Offline mrduc1198

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Re: Carb to Air Box Connection
« Reply #2 on: 30.05. 2012 19:44 »
Hi John:

Would I be able to trouble you for a picture? either fitted on or it's own.

Interesting about the frame number.  Mine has made its way down to Australia.

thanks

Offline gavinoz

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Re: Carb to Air Box Connection
« Reply #3 on: 31.05. 2012 03:51 »
John, I also would also appreciate to see the photo, but in situ on bike.

I have a rigid frame (1949), but with an A7S 1951 motor. The frame accessories look to come from an even earlier model, as the hole in the air box is forward facing, rather than the L shape. currently having an overlarge 376 on, there is no room for a hose, as the airbox hole is very close and offset below the carb mouth. I will fit a 276 on, but suspect that the later model engine will not align with the early air box. (in which case I will have to obtain a later airbox with the L hose)

Thanks, Gavinoz
Rigid A7S, 57 A10 in pieces
Australia

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Re: Carb to Air Box Connection
« Reply #4 on: 31.05. 2012 06:38 »
Hi guys. I will try and get a picture of the airbox hose in situ and will post. I am away for the next couple of days so probably will be on Saturday. The hose fits into the airbox hole and just goes over the carb mouth so is not very big.

Gavinoz, your correct, the airbox for the long stoke bikes had the hole for the air hose directly behind the carb. Here is a picture of what it looked like. You are probably right that the later short stroke engine carb mounting won't line up.

mrduc1198. do you know if your frame was distpatched to Australia from the factory or did it make its way there later on ?

Cheers, John
1931 Ariel VB31, 1935 Triumph 5/3 project, 1946 Ariel Square 4, 1952 Norton Model 7, 1953 BSA A10 Super Flash, 1954 Ariel VH

Offline mrduc1198

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Re: Carb to Air Box Connection
« Reply #5 on: 31.05. 2012 12:10 »
Hi John:

Sorry, I don't know the history of how the bike made its way to Australia.

I've fit the air box back on and you can see the carb and air box are practically kissing.

Offline Beezageezauk

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Re: Carb to Air Box Connection
« Reply #6 on: 31.05. 2012 14:04 »
Hi there,

It looks as though you need part number 67-4546 which is described as the "Air Filter Ferrule" in my 1949 parts book.  Maybe if you quote that number to some parts suppliers you might have some luck.

Unfortunately my scanner is out of action so I can't show you it but it certainly looks as though it would connect between the carb and filter housing shown in your picture.

Beezageezauk.

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Re: Carb to Air Box Connection
« Reply #7 on: 01.06. 2012 08:37 »
Hi mrduc1198, I can not see very clearly in your picture but it looks like there is a metal tube protuding from the airnox towards the carb that is not on the airbox for the early rigids. It looks like the tube on a later swinging arm airbox. Does the airbox / battery carrier look like the picture I posted or like the one on the parts book page that I attach below ?
1931 Ariel VB31, 1935 Triumph 5/3 project, 1946 Ariel Square 4, 1952 Norton Model 7, 1953 BSA A10 Super Flash, 1954 Ariel VH

Offline mrduc1198

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Re: Carb to Air Box Connection
« Reply #8 on: 01.06. 2012 10:57 »
Hi John:

Thanks for your time, all information is interesting and helpful.

The air box does not look like the red one that you uploaded.  The red one looks to just have a flush cut hole on the air box whereas the one on mine has a raised hole (see pic).  I don't believe it's like what's in the manual page either.  There are two holes on the tab below the battery holder whereas the red one and manual page only have a single hole on the tab.  Hard to say if the two holes are original just by looking.

thanks
tom

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Re: Carb to Air Box Connection
« Reply #9 on: 02.06. 2012 07:50 »
Hi Tom.

Yes, all the air boxes I have seen for the early A7 has the flush cut hole on the air box that the rubber connector clips into. The rubber is a round tube at the carb end and swells out to a oval shape the same as the hole with a lip on it to hold it in the hole. I have never seen one like yours. Perhaps it has been modified or maybe somebody else will know ?
1931 Ariel VB31, 1935 Triumph 5/3 project, 1946 Ariel Square 4, 1952 Norton Model 7, 1953 BSA A10 Super Flash, 1954 Ariel VH

Offline mrduc1198

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Re: Carb to Air Box Connection
« Reply #10 on: 03.06. 2012 08:57 »
Hi John:

Thanks for all the responses and information.  I'll keep digging around and see what I can find.

tom

Offline steve.link

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Re: Carb to Air Box Connection
« Reply #11 on: 08.11. 2012 00:07 »

Offline Housewiz

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Re: Carb to Air Box Connection
« Reply #12 on: 11.12. 2012 21:20 »
I have the added issue of taking a std A10 swingarm air box, removing the inlet pipe on the air box itself, patching that hole, then fabbing an identical inlet pipe and aligning both with the two 276 carbs I plan on installing.

Who has some ideas for that crazy idea??

Thanks,

Steve

Offline Tomcat

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Re: Carb to Air Box Connection
« Reply #13 on: 12.12. 2012 09:21 »
G'day MrDUC, I purchased mine from JeffAlanHunter (as above post) I think it was Brian on here who helped me obtain the unobtainable! 67-4546
1959 Super Rocket, 1990 NX650