Britbike forum

Classic British SparesKlempf British PartsBaxter CycleBritBike Sponsor SteadfastCyclesThe Bonneville ShopLowbrow CustomsSRM EngineeringGirling Classic MotorcycleLucas Classic MotorcycleHepolite PistonsIndustrial tec supply

Upgrade your membership: Premium Membership Gold Membership


New Sponsor post
Cyber Monday Sale - 10% off at The Bonneville Shop
by The Bonneville Shop - 11/29/21 5:34 pm
New FAQ post
How to find my own threads?
by reverb - 11/20/21 3:55 pm
Manuals on DVD - Buy 4 for 3
All 4 DVD Manual
Member Spotlight
kevin
kevin
ohio, usa
Posts: 5,829
Joined: December 2013
ShoutChat
Comment Guidelines: Do post respectful and insightful comments. Don't flame, hate, spam.
Top Posters(30 Days)
Rohan 84
NickL 69
Top Likes Received (30 Days)
kevin 23
Newest Members
bradders, tizianouk, Breeze, FORTYTWO, TomV
11,929 Registered Users
Who's Online Now
3 members (TR6Ray, Stuart Kirk, BeezaBryan), 19 guests, and 20 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Joined: Aug 2001
Posts: 376
Likes: 1
C
Britbike forum member
OP Offline
Britbike forum member
C
Joined: Aug 2001
Posts: 376
Likes: 1
I have a 1939 Francis Barnett Cruiser with the Villiers Mark 18A engine. This has the AMAL type 6 carburetor on it. I am looking for the needle jet size, I cannot find it in any of the information I have and it is not marked on the jet that is in the carburetor. The parts book only lists it as part 4/061 but no size.

British motorcycles on eBay
Joined: Sep 2013
Posts: 3,446
Likes: 159
Q
Britbike forum member
Offline
Britbike forum member
Q
Joined: Sep 2013
Posts: 3,446
Likes: 159
there is a Frances Barnett villiers carb. referenced here
https://partsbooks.britishonly.com/...amal/settings/1936/1936-1939combined.pdf

Joined: Aug 2001
Posts: 376
Likes: 1
C
Britbike forum member
OP Offline
Britbike forum member
C
Joined: Aug 2001
Posts: 376
Likes: 1
There is a reference to the 1938 model, it uses a 0.107 needle jet. No details on the 1939, but it looks like the 0.107 jet is a good starting point.

Thanks Quinten!

Joined: Sep 2013
Posts: 3,446
Likes: 159
Q
Britbike forum member
Offline
Britbike forum member
Q
Joined: Sep 2013
Posts: 3,446
Likes: 159
happy to help ,
is this a brass body carb ?

AMAL still has 4/061 jets listed in 7 sizes .

Joined: Aug 2001
Posts: 376
Likes: 1
C
Britbike forum member
OP Offline
Britbike forum member
C
Joined: Aug 2001
Posts: 376
Likes: 1
Yes it is and it is in great shape other than a clogged pilot jet and perhaps a worn needle jet.

Joined: May 2017
Posts: 150
Likes: 31
V
Britbike forum member
Offline
Britbike forum member
V
Joined: May 2017
Posts: 150
Likes: 31
Can I ask for details of your Type 6 carb? This would appear to be an aftermarket carb as Villiers introduced their own new carb for the 18A but with WWII starting so soon after the 18A introduction the new carb was only around for the blink of an eye. It’s a good thing AMAL produced an alternative as Villiers never continued with the 18A “Heavyweight” carb and they’ve just disappeared as have any existing spares.
Could you tell us what numbers AMAL stamped on this carb?

I’m also curious about seven sizes for needle jet 4/061. I’ve always been under the impression that a 4/061 was a fixed size.

Cheers,

Joined: Aug 2001
Posts: 4,302
Likes: 59
R
Britbike forum member
Offline
Britbike forum member
R
Joined: Aug 2001
Posts: 4,302
Likes: 59
AMAL do seem to list them in a number of sizes.

https://amalcarb.co.uk/pre-Monobloc/76-276-series/jets/needle-jet.html

Its difficult to tell if they are numbered as to size.
Be a PITA if they are not ...
https://amalcarb.co.uk/media/catalo...5fb8d27136e95/4/-/4-061-needle-jet_6.jpg

Joined: May 2017
Posts: 150
Likes: 31
V
Britbike forum member
Offline
Britbike forum member
V
Joined: May 2017
Posts: 150
Likes: 31
Mystery solved.

I only have the original factory AMAL literature so never look at the Burlen site. The original factory literature carefully differentiates between the 4/061 needle jet and all the others.

It refers to the 4/061 as Std for all the Type 6 carbs and uses the other nomenclature mentioned above for other types. For example the T10TT carb on the 1946-50 KTT Velo uses a .109 needle jet. 4/061 isn't mentioned. As another example, the .107 needle jet mentioned above is listed for the little Type 361 carbs used on the Vincent/NSU's of 1954. Again, 4/061 isn't mentioned.

Somehow Burlen have folded the lot together but original AMAL literature does not. I'll just have to be careful what source I refer to won't I.

Joined: Aug 2001
Posts: 376
Likes: 1
C
Britbike forum member
OP Offline
Britbike forum member
C
Joined: Aug 2001
Posts: 376
Likes: 1
I do not know how to post a picture, but this writeup on the Cruiser 45 has a picture of the AMAL carb fitted to the 18A engine:

http://www.starfield181.co.uk/Notes%20on%20a%201939%20Francis%20Barnett%20Cruiser%20Model%2045.pdf

It is a really odd setup, but is original to the Cruisers fitted with the 18A engine. The Goddard book on the Francis Barnett indicates the carb to be a 6/125.

Joined: Sep 2013
Posts: 3,446
Likes: 159
Q
Britbike forum member
Offline
Britbike forum member
Q
Joined: Sep 2013
Posts: 3,446
Likes: 159
from ; The Book of the Villiers Engine - A Complete and Fully Illustrated ...
https://books.google.com/books?id=J...=villiers%20Mark%20XVIII%20A&f=false
.

Joined: May 2017
Posts: 150
Likes: 31
V
Britbike forum member
Offline
Britbike forum member
V
Joined: May 2017
Posts: 150
Likes: 31
A picture equals a thousand words. All has become clear. Francis Barnett couldn't have used the original Villiers Heavyweight carb on the Cruiser anyway. Like all Villiers carbs it had an integral floatchamber and couldn't be mounted at an angle to be hidden under the Cruiser bodywork as shown in that photo.
It appears Francis Barnett turned to AMAL for a solution who in turn provided a carb in line with a fad of the day.

For a short period in the late 1930's the British motorcycle factories experimented with mounting AMAL carbs on their side as shown in the picture. Mainly this was on tall four stroke singles where there wasn't enough room under the tank for the usual vertical mounting. It worked well enough when the carbs were new but quicjkly became frustrating with a little wear leading to much frustration with flooding, slides jamming and of course erratic carburation from odd wear pattterns in the needle jet.. It was not a happy experiment.

Owners always talked of having to take extreme care to get everything just so and to keep it that way. The concept had very few enthusiasts.

Nowadays it is possible to have carb bodies re sleeved with a stainless steel sleeve and I suspect you may have to go down this path as well as fitting a new standard 4/061 needle jet.
Best of luck.

Joined: Aug 2001
Posts: 4,302
Likes: 59
R
Britbike forum member
Offline
Britbike forum member
R
Joined: Aug 2001
Posts: 4,302
Likes: 59
Ain't that all the truff !!
I've got one of these, but for a prewar Enfield (4 stroke) project, and I'd been contemplating
that fitting fool injection may be simpler. !

However, about new everything has cured most of the ailments, and a new fuel needle seat may fix some more issues.
I didn't quite appreciate how critically important the exact fuel level was until I met this jigger.
And I've met a few folks who have them working, so it is actually possible.

[Linked Image from i.postimg.cc]

It is quite a small bore carb, so it remains to be seen how successful this will be.

Joined: Aug 2001
Posts: 376
Likes: 1
C
Britbike forum member
OP Offline
Britbike forum member
C
Joined: Aug 2001
Posts: 376
Likes: 1
Thanks all, I've got a 0.107 needle jet coming, we shall see how it goes. The carb is in great shape, but getting the float chamber vertical is a real challenge, there is no room to fit a wrench when the carb is in place, so it is trial and error before you get it right, then as has been said, you really work to keep it right.

Earlier Cruisers did have the Villiers carb on them, they had a different cylinder than the later models so it was able to work. Here is a link to a picture of one:

https://www.andybuysbikes.com/archivehtml/5536frt.html#

I think any Cruiser, early or late, is not for the faint of heart (restoration or servicing wise), plus it is a surprisingly small bike (from handlebar to seat) so those over 6' may not fit too well.

Joined: Sep 2013
Posts: 3,446
Likes: 159
Q
Britbike forum member
Offline
Britbike forum member
Q
Joined: Sep 2013
Posts: 3,446
Likes: 159
[Linked Image from andybuysbikes.com]

Joined: Aug 2001
Posts: 376
Likes: 1
C
Britbike forum member
OP Offline
Britbike forum member
C
Joined: Aug 2001
Posts: 376
Likes: 1
That's the picture Quinten, quite a bit going on under the bonnet!

Joined: Aug 2001
Posts: 4,302
Likes: 59
R
Britbike forum member
Offline
Britbike forum member
R
Joined: Aug 2001
Posts: 4,302
Likes: 59
And the whole bike, for those not familiar.

[Linked Image from andybuysbikes.com]

Look at all that enamel that needs polishing !
Strange place for the muffler

But we wander ...


Moderated by  Jon W. Whitley 

Link Copied to Clipboard
Job CycleBritish Cycle SupplyMorries PlaceKlempf British PartsPodtronicVintage MagazineBSA Unit SinglesBritBike SponsorBritish Tools & FastenersBritBike SponsorBritBike Sponsor






© 1996-2021 britbike.com
Powered by UBB.threads™ PHP Forum Software 7.7.5