BritBike Forum logo
BritBike Sponsor BritBike Sponsor BritBike Sponsor
BritBike Sponsor

BritBike Sponsor

BritBike Sponsor
BritBike Sponsor BritBike Sponsor BritBike Sponsor
Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Photo posting tutorial

Shout Box
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Member Spotlight
bitsa110
bitsa110
Far Northern California
Posts: 25
Joined: October 2004
Show All Member Profiles 
Newest Members
craighewitt, wayne5, timmy dunne, T120rIan, Irish Murph
9509 Registered Users
Top Posters(30 Days)
NickL 95
Stuart 92
Boomer 69
Popular Topics(Views)
259,956 mail-order LSR
Forum Statistics
Forums33
Topics62,547
Posts602,643
Members9,509
Most Online3,995
Feb 13th, 2017
Like BritBike.com on Facebook

Previous Thread
Next Thread
Print Thread
Rate This Thread
#402565 - 11/07/11 10:59 pm Convert a Dual Carb to Single Carb???  
Joined: Feb 2010
Posts: 37
Paula C. Buls Offline
BritBike Forum member
Paula C. Buls  Offline
BritBike Forum member

Joined: Feb 2010
Posts: 37
Texas
This is my first post in quite some time. I have had a '69 Lightning that I purchased as a bitsa bike a few years ago and kept running as a daily rider until I went back to grad school and had to put it aside for awhile.

Now, I'm done with school and wanting to put the bike into good running order. I've decided to tear into it and do some significant redo as part of getting it in top shape. One of the things that I had always been concerned with when I had the bike running previously was that it had an incorrect tank on it (I believe the tank on it was actually a rocket 3 tank) I now have a correct tank for it and am collecting other needed parts. It had been missing the engine steady stay and while I had the tank off discovered the reason for its missing. The mounting tab on the head is broken off. I don't know if this is something that can be repaired or if I should start scouting for a good used replacement head to rebuild. (I am planning on tearing down the engine to redo the bottom end and clean the sludge trap and make sure evrything is in reasonable condition)That of course leads to the question of whether I am better off converting to a single carb head and doing away with some of the headaches of having the dual carbs. The existing carbs are not in great shape and at the least will need to be resleeved. I am not interested in achieving maximum speed out of this bike and am more interested in fuel economy and reliability. At the risk of starting a huge debate I was wondering about the pros and cons of converting a lightning to a thunderbolt.

Any thoughts?

Thanks in Advance,

Paula


1969 BSA Lightning "Penelope"
1978 BMW R80/7 "Freyja"
Support Your #1 BritBike Forum!
Membership Type! Free
Member
Premium
Member
Premium Life
Member
Vendor
Member
Site
Sponsor
Recognition No Premium Member Premium Life member (5 years) Vendor Member Site Sponsor Membership
Post commercial threads No No No Yes Yes
Custom title No Yes Yes Yes Yes
Upload avatar & photos No Yes Yes Yes Yes
Link avatar & photos Yes Yes Yes Yes Yes
Private Message Storage: 10 100 100 100 100
Length of signatures 255 600 600 600 600
Removes this very advert island between post 1&2 No Yes Yes Yes Yes
Price Free $12.90/year $105.00 No End
$55.00/5 years
$210.00/year
($17.50/month)
Email
Click on button >>
  Premium Member Premium Life member Vendor Member Site Sponsor Membership
#402586 - 11/08/11 12:49 am Re: Convert a Dual Carb to Single Carb??? [Re: Paula C. Buls]  
Joined: Aug 2001
Posts: 3,348
BONZO R.I.P. Offline
BritBike Forum member
BONZO R.I.P.  Offline
BritBike Forum member

Joined: Aug 2001
Posts: 3,348
Michigan, USA
if you are not looking for performance or correctness and you are looking for a more troublefree ride then you are on the right track.The only downside I can see is the sidecovers for the twin carb head might leave a bit of a gap . I rode mine like that for several seasons and really enjoyed it .I'd definitely recomend the stock 928 carb .the bike will have a different personality but it sounds like what you are after .

FWIW-BONZO

#402587 - 11/08/11 12:50 am Re: Convert a Dual Carb to Single Carb??? [Re: Paula C. Buls]  
Joined: Jul 2001
Posts: 11,270
Lannis Online content
Life member
Lannis  Online Content

Life member

Joined: Jul 2001
Posts: 11,270
Central Virginia
I've often thought about it; seems like I always have A65s with dual-carb heads even though I'd be just as happy with a single carb.

I've got a single-carb head sitting on the shelf, and it would be easy to rejet one of my carb bodies for it, and just use it on the Firebird. No more having to sync carbs, and do everything twice, etc.

But I've never gone to the trouble. To be honest, a properly sorted set of Amals with sleeves will last a long time (been 30,000+ miles so far and still starting and idling easy). And I guess I do sort of like that little bit of top-end "kick" that you get on a dual-carb bike; and two carbs aren't really that much trouble.

But if you need a new head anyhow, and have to source one, NOW would certainly be the time to convert. Just make sure you get the right size carb and jet it right.

It should be fun "getting back into" the old bikes!

Lannis


"Peace of mind? It's a piece of cake!"
#402588 - 11/08/11 1:06 am Re: Convert a Dual Carb to Single Carb??? [Re: Lannis]  
Joined: Mar 2006
Posts: 3,566
raf940 Offline
BritBike Forum member
raf940  Offline
BritBike Forum member

Joined: Mar 2006
Posts: 3,566
gastonia nc
hi..i have a 1968 A65 bitsa...it has lightning frame and engine but the box of bits had a single carb head ..i put an AMAL 928 on it and i really love it...not as fast as my T120 but really tractable and easy to tune....

Last edited by raf940; 11/08/11 1:07 am.

1972 Triumph T120
1968 BSA A65
1968 MGB Roadster
1979 Chevrolet Camaro Berlinetta
1969 Honda Mini Trail
1939 farmall f30 tractor
2004 Honda Shadow Aero
1972 BSA Thunderbolt
1975 yamaha xs650b
#402609 - 11/08/11 2:41 am Re: Convert a Dual Carb to Single Carb??? [Re: Paula C. Buls]  
Joined: Dec 2005
Posts: 458
Bob~NJ Offline
BritBike Forum member
Bob~NJ  Offline
BritBike Forum member

Joined: Dec 2005
Posts: 458
Camden NJ USA
Hi Paula,

Would really like to see a pic of the broken head steady tab on your engine. Never seen one before. Anything can be repaired......

Cheers~Bob


A65LB
#402677 - 11/08/11 1:54 pm Re: Convert a Dual Carb to Single Carb??? [Re: Bob~NJ]  
Joined: Feb 2010
Posts: 37
Paula C. Buls Offline
BritBike Forum member
Paula C. Buls  Offline
BritBike Forum member

Joined: Feb 2010
Posts: 37
Texas
Here's the pic.



I'm open to repairing if that's a reasonable option. I'm dubious about buying a used head and then still having to sort that one out.

Cheers,

Paula


1969 BSA Lightning "Penelope"
1978 BMW R80/7 "Freyja"

Moderated by  Allan Gill, Mike Carter 

Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
BritBike Sponsor BritBike Sponsor BritBike Sponsor
BritBike Sponsor

BritBike Sponsor

BritBike Sponsor
BritBike Sponsor BritBike Sponsor BritBike Sponsor
BritBike Forum logo
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.040s Queries: 15 (0.009s) Memory: 1.6191 MB (Peak: 1.7129 MB) Zlib disabled. Server Time: 2017-02-24 08:19:22 UTC