BSA Owners' Club Workshop Discussions

Gallery => Which BSA do you ride? => Topic started by: Plammiman on 03 Apr, 2020, 11:20

Title: A10 fuel taps
Post by: Plammiman on 03 Apr, 2020, 11:20
I am looking for some recommendations on the best way to operate my fuel taps on my A10. I have a non reserve tap in the near side position that is located in a well lower than the rest of the tank. The other tap on the off side is a reserve tap with a double push pull plunger, one has a twist and lock and one a straight push pull on this tap. First question is do I need a reserve tap? Are the taps in the right location? Should I run with both taps on? On the reserve tap any ideas which is the main and which is the reserve without striping it out to flow check it? Be interested in any views
Phil
Title: Re: A10 fuel taps
Post by: idie on 03 Apr, 2020, 12:07
Don't run with both taps on as you will have no reserve. It doesn't matter which side that you use as the main tap. The fuel will run down until the only fuel in the tank will be that which is trapped by the hump on the bottom of the tank. Then you use the other side to the main tap. There should be enough for about 20 miles left. This is how it works on my BSAs.
Title: Re: A10 fuel taps
Post by: DAVE BRADY on 03 Apr, 2020, 13:27
I have always considered the right hand tap as the main tap with the left tap that sits in a lower bit of the tank as the reserve.
I stand to be corrected, but I do not think that A10s or A65s ever had a tap with a reserve position (and a tube) as standard.
The idea may be that the left hand tap can be opened whilst riding and keeping control with the right hand - more dextrous?
When fitting the taps I try to position them so that hey can be operated easily whilst seated. 
Have you ever set off with the fuel off?  I have and being able to get the fuel on is always helpful.

Dave.
Title: Re: A10 fuel taps
Post by: Plammiman on 04 Apr, 2020, 18:01
Thanks Dave, do you ride with the right on only and then switch to the left when the right side of the tank is down to minimum. I assume you can get a high proportion of the fuel out of the right tap until the hump in the middle splits the fuel tank fuel quantity leaving the remaining left side fuel quantity as the reserve?
Title: Re: A10 fuel taps
Post by: DAVE BRADY on 04 Apr, 2020, 19:02
Yes, right on only then as the bike starts to show signs of fuel starvation pull the left one on and head for the filling station.
The trick is to refill before going on reserve so taking note of mileage can help.  I think I get about 50mpg from my A65 and the tank is 4 gallons so I start looking for fuel at about 150 miles.  This means I have plenty of time to find a filling station - needed more in rural France than UK.

Dave.

I see you have the small tank so more attention to fuel consumption needed.
Title: Re: A10 fuel taps
Post by: chaz on 06 Apr, 2020, 12:55
my dilemma at the moment, the A10 has been off the road for years since the old fuel pipe rotted and the carbs corroded due to the ethanol and no use.
Ive got a 1/4BSP fitting on front right which was main feed with a new brass tap on/off, there was a seperate tube coming out from the left hand 1/4BSP but I cant undo, had a length of pipe with a bolt in the end to plug, until the pipe rotted/melted, sticky goo feeling.
then there is a 1/8BSP plugged hole on the back left side.
do I go a pair of pipes from the 1/4 into a union then a seperate filter before the carb or blank off both 1/4 and feed from 1/8 through a filter. this way its rock the bike to use reserve in opposite side
or balance pipe from the 1/4BSP outlets and then feed from 1/8th
currently running a 376 monoblock with extension chamber.
Title: Re: A10 fuel taps
Post by: DAVE BRADY on 06 Apr, 2020, 17:36
Hi Chaz,

Is this a standard A10 tank?  There seems to be a lot of tap holes.
A problem with having only one tap is getting the trapped fuel across.  Rocking the bike will really work and you will have to lay the bike on its side to get fuel across.
B40s only had one tap and I can remember doing as a lad when petrol was 33p a gallon this but a B40 is a lot lighter than an A10.

Dave.
Title: Re: A10 fuel taps
Post by: chaz on 06 Apr, 2020, 19:23
Dave
cant say about authenticity of tank, Ive had the bike around 8 years and before that I knew it for another 3 in the same condition. Its a bobber with Aprilia RS forks and cast wheels with disc brakes, I would say its a BSA tank but not badged twin holes for round badges.
as I said before, one front outlet wont come undone and has a straight down pipe. so how effective is the balance pipe at the front?
Ive brought kit down to play with so may link the front and feed from rear but not much room for an inline filter
Title: Re: A10 fuel taps
Post by: DAVE BRADY on 06 Apr, 2020, 19:59
Chaz,

I think that a Bantam model had a flexible pipe connecting the two sides of the tank with one tap towards the rear.  This idea was probably utilised on other bikes with what is effectively a split tank.  As this was a 'proper' fitment it will have worked.  I would imagine that the pipe would have been the same as needed to feed the carb other wise the fuel would be used quicker than it could get from one side to the other.
If the connecting pipe is the same as your carb feed then it should all work fine.  The connecting pipe should be as straight a possible to avoid debris and water from sitting in a low point.
I hope this is helpful.

Dave. 
Title: Re: A10 fuel taps
Post by: chaz on 06 Apr, 2020, 22:06
Thanks Dave, get off of this shift and play again at the weekend, hope this helps Phil's original post. When I've had two taps before, it always bugged me that the levers were in opposite directions when off.