BAP Tap and bowl drain leaks.

Woody850

Woody850

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After having a constant dribble from carbs and non sealing taps I decided to order BAP taps and reseal the Mk 1 carbs. Once finished the (Premier) float bowls wouldn't seal at the drain and petrol was seeping up the thread from the banjo on the tap AND seeping from the joint where the dowty washer holds the tap in the tank.

So far I confronted the issue on the float bowls with using the old plastic screw plugs with the old thick green washers which had first been given a flat surface on some emery on a glass plate. To tighten them I use an old two shilling piece which seems to be made for the job.
Can these green gaskets be sourced still? In the Amal pack were only thin hard red ones supplied!

Now to the taps, my only theory to them is to use silikon tape to seal the threads but I wasn't enthralled by the look of the inverted conical joint where my banjo is bolted in to.
For now I have had enough inhaling of petrol, to the point I have a head full of it
and would dearly be glad to hear your input.
 
Gas PTFE tap is double the thickness of plumbers PTFE tape in the UK and will seal threads against petrol. As for the dowty washer if that's not sealing either you are not tightening the tap enough, which is understandable as BAP's can break, or you need another source for the dowty washer with a better sealing ring material. I use a copper clad washer which crushes and the inner O ring is pressed against the thread.

Carburation/Fuel :: Fuel Taps and Parts :: Tap Parts :: 1/4" BSP Tap Parts :: Crush Copper/Rubber Washers for Fuel Tap 1/4"

Crush Copper/Rubber Washers for Fuel Tap 1/4" Sealing washer for 1/4" petrol tap - Price for ONE washer. OEM: 70-7351, E7351 Rubber seal encased in copper, when fitted to fuel tap and screwed into tank, the washer crushes effecting a good seal. Hole id 1/
www.feked.com www.feked.com
 
Woody850 said:
In the Amal pack were only thin hard red ones supplied!
Click to expand...

Unless they've changed the colour then the largest of the two "thin hard red" fibre washers often included in the gasket packs (upper left in the link pic.) is not intended for the drain plug.
amalcarb.co.uk

Shop Gasket / Washer Kit Online | Gasket sets | AMAL Carburetters

Gasket / Washer Kit
amalcarb.co.uk amalcarb.co.uk
It is for the banjo to float bowl joint for alcohol fuel as the white filter with the sealing flange is then not used.
The green washer (lower right in the link pic.) is the drain plug washer.

The float bowl washer could also be red now...🙄

Carburation/Fuel :: Amal Carb Parts & Jets :: Concentric Mk1 Parts :: Amal Metal Float Bowl Drain Plug - 600/900 Carburettors

Metal Float bowl drain plug, for 6 and 9 Series carburettors. OEM: 622/155, 6/155
www.feked.com www.feked.com
...but shouldn't be as thin and hard as the alcohol banjo washer.


Woody850 said:
petrol was seeping up the thread from the banjo on the tap AND seeping from the joint where the dowty washer holds the tap in the tank.
Click to expand...

Ordinary Dowty washers are not intended to seal a thread because the continuous lip has to cross over the crest of the thread at some point.
The correct type to use would be:

Bonded Seals Thread Seal

www.hitechseals.com www.hitechseals.com
 
Last edited:
If you're using a Dowty washer without a backing washer it may not stop the leak. The threads are very course but a lot of the proper teflon tape stop the leak. I just use the Dowty washers and backing washers and make sure the sealing area of the tank is smooth.

Dowty 06.5329
Backing Washer 00.0167

I don't know if Norton ever specified the backing washer, but Triumph and BSA did and AN sells them.
 
kommando said:
Gas PTFE tap is double the thickness of plumbers PTFE tape in the UK and will seal threads against petrol. As for the dowty washer if that's not sealing either you are not tightening the tap enough, which is understandable as BAP's can break, or you need another source for the dowty washer with a better sealing ring material. I use a copper clad washer which crushes and the inner O ring is pressed against the thread.

Carburation/Fuel :: Fuel Taps and Parts :: Tap Parts :: 1/4" BSP Tap Parts :: Crush Copper/Rubber Washers for Fuel Tap 1/4"

Crush Copper/Rubber Washers for Fuel Tap 1/4" Sealing washer for 1/4" petrol tap - Price for ONE washer. OEM: 70-7351, E7351 Rubber seal encased in copper, when fitted to fuel tap and screwed into tank, the washer crushes effecting a good seal. Hole id 1/
www.feked.com www.feked.com
Click to expand...
Do youput a flat washer under the copper clad as per the dowty set up?
 
marshg246 said:
Dowty 06.5329
Backing Washer 00.0167
Click to expand...

Although AN sells "Dowty type" 06.5329 washers, as far as I know, Norton never used Dowty washers (probably for the simple reason that a standard Dowty washer doesn't seal the thread as stated previously).

The sealing washers shown with AN taps are the Stat-O-Seal type.
https://andover-norton.co.uk/en/shop-details/14968/fuel-tap-reserve-with-sealing-washer
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk

The later parts drawings (850 Mk3 drawing) show what appear to be Stat-O-Seals, not Dowty washers...
BAP Tap and bowl drain leaks.
...however, they are often referred to as "Dowty type" even though they are a crush washer (thus requiring a backing 'compression' washer)...
www.ebay.co.uk

2X PETROL TAP SEALING WASHERS DOWTY TYPE 1/4" BSP - BSA NORTON TRIUMPH - 70-7351 | eBay

<p></p> <p>WASHER - Universal</p> <p></p> <p>Pair of Petrol Tap Sealing washers (Dowty type)</p> <p>1/4" BSP</p> <p>OEM: 70-7351</p>.
www.ebay.co.uk

Woody850 said:
Do youput a flat washer under the copper clad as per the dowty set up?
Click to expand...

Yes, the flat washer helps to compress the rubber of the soft copper-clad type tightly into the thread something the Dowty washer won't do because it has a solid ring.

Carburation/Fuel :: Fuel Taps and Parts :: Tap Parts :: 1/4" BSP Tap Parts :: Crush Copper/Rubber Washers for Fuel Tap 1/4"

Crush Copper/Rubber Washers for Fuel Tap 1/4" Sealing washer for 1/4" petrol tap - Price for ONE washer. OEM: 70-7351, E7351 Rubber seal encased in copper, when fitted to fuel tap and screwed into tank, the washer crushes effecting a good seal. Hole id 1/
www.feked.com www.feked.com

Edit: https://www.earls.co.uk/earls/accessories/seals.html
 
Last edited:
I was somewhat perturbed on opening the gasket pack as I couldn't imagine having a hard red washer and expected to see what your picture shows L.A.B. but not questioning the fact I used the only washer which fitted.
 
Woody850 said:
Do you put a flat washer under the copper clad as per the dowty set up?
Click to expand...
I don't, the copper is both top and bottom so being soft copper will more likely seal than steel. Put too many items between the tap and the tank and you run out of thread engagement with the tank threaded insert.
 
kommando said:
I don't, the copper is both top and bottom so being soft copper will more likely seal than steel. Put too many items between the tap and the tank and you run out of thread engagement with the tank threaded insert.
Click to expand...
I am sure that I have some lying around which got collected over the years so I will report back!
 
Although the copper crush washer can be fitted without a backing washer as in the picture below, the contact face of the nut isn't sufficiently large enough to uniformly crush the washer so I prefer to use a backing washer whenever possible.
BAP Tap and bowl drain leaks.
 
L.A.B. said:
Although the copper crush washer can be fitted without a backing washer as in the picture below, the contact face of the nut isn't sufficiently large enough to uniformly crush the washer so I prefer to use a backing washer whenever possible.
BAP Tap and bowl drain leaks.
Click to expand...
I think you are right there. Can you say anything to the mating surfaces on the BAP tap's, mine do not look good at all and I lack a machine to give them the correct inner convex angle.
 
Woody850 said:
Can you say anything to the mating surfaces on the BAP tap's, mine do not look good at all and I lack a machine to give them the correct inner convex angle.
Click to expand...

You could try lapping the taper with a (spare?) spigot and metal polish. The taps are new so there shouldn't be anything wrong with the seatings. Maybe new spigots would help to cure the leakage.

www.ebay.co.uk

PETROL TANK TAP 1/4 BSP SPIGOT AND NUT for BSA TRIUMPH NORTON | eBay

Find many great new & used options and get the best deals for PETROL TANK TAP 1/4 BSP SPIGOT AND NUT for BSA TRIUMPH NORTON at the best online prices at eBay! Free delivery for many products.
www.ebay.co.uk
 
L.A.B. said:
You could try lapping the taper with a (spare?) spigot and metal polish. The taps are new so there shouldn't be anything wrong with the seatings. Maybe new spigots would help to cure the leakage.
Click to expand...
I will certainly give that one a go.
 
My BAP "type" taps worked well first couple of seasons, then sat on my other tank for a season. When I returned them to service this season they leaked from the inssternal rubber seals. Could not find a source to replace them so have not used them again. Seems the rubber may have contracted after drying out. Unlikely these are real BAP as the rubber seals on authentic have a moulded in shape, mine are just flat with two holes.
 
Tornado said:
My BAP "type" taps worked well first couple of seasons, then sat on my other tank for a season. When I returned them to service this season they leaked from the inssternal rubber seals. Could not find a source to replace them so have not used them again. Seems the rubber may have contracted after drying out. Unlikely these are real BAP as the rubber seals on authentic have a moulded in shape, mine are just flat with two holes.
Click to expand...
I use real BAP taps and are very happy with them .
 
I would be interested in a supplier in Europe too, as the one I bought from Feked failed without prior warning (MAIN position acting as RESERVE, so no reserve when you need it!).
 
laurentdom said:
I would be interested in a supplier in Europe too, as the one I bought from Feked failed without prior warning (MAIN position acting as RESERVE, so no reserve when you need it!).
Click to expand...
Initially mine came from Norton Motors.de and I believe them to be original. In my search out of curiosity I found companies selling "BAP type taps" which proved the circulation of copies.
 
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