petrol tap - unblocking ?

[hoogerbooger]

any suggestions on best way to decrud the internals of a petrol tap ?

Just taken tank off my B40 after 18 yrs or sitting with some fuel in it. Plunger on the tap didn't want to open. bit of WD40 and a wiggle to release it ........ but  no fuel came out. Seems to be blocked.... so have emptied through filler. I stuck the fuel pipe back on the tap and blew threw....a bit of air got through but not much.

Not obvious to me how tap is fixed. Is the tap-hole in the tank threaded ? or is there a nut on inside ? ( which would seem impossible to get to). Do you twist the tap anti-clockwise to remove ?

Should I presume the fibre washer will need replacing if the taps is taken off ?

advice welcomed

[JulianS]

The tap screws into a threaded boss in the tank, no nuts involved. There should be a fine mesh filter attached to the tap and this is probably blocked.

You can use a fibre washer between tap and tank though a Dowty sealed washer is a better option.  I also wrap the thread with PTFE tap to provide extra seal.

[hoogerbooger]

Ta. Dowty washer probably what's there now... now I look closer. Presumably these need to replaced any each time the tap comes off ?

Just took the plunger out. Cork looks intact. I read that with ethanol they are more prone to shrinkage/dripping. Is this a certain problem ? as in no point trying to make do with the existing tap ?

(I don't like the idea of replacing parts if its avoidable  .... as the the bike will becoming less original.)

[JulianS]

I found that the cork seals tended to drip/seep fuel even after being renewed so replaced with lever taps on my A10.

Some replacement corks are better quality than others.

With the original type taps you sometimes find that when screwed into the tank the plunger is in an inconvenient difficult to reach position, usually facing inwards. Sometimes this can be remedied using a different thickness washer.

Good quality replacement taps with a large nut can be positioned so that the lever is convenient ans also dont leak.

[ROYC]

I am confused as to which on of these (if any) taps is best to replace my dripping pull on taps.  https://www.feked.com/carbs-fuel/fuel-taps/1-4-taps/   

Thanks.
Roy.

[JulianS]

I used the third one down - the reserve type - on my A10, did not leak but it was poorly made, the hole in the metal part of tap was not deburred and the hole in rubber seal did not completely line up with the hole in the tap. Problems rectified with fettling but at that price it is hard to complain.

You will need a 1/4BSP to 3/8 BSP adaptor to go in the tank.

Below is what they look like inside.

[ROYC]

I used the third one down - the reserve type - on my A10, did not leak but it was poorly made, the hole in the metal part of tap was not deburred and the hole in rubber seal did not completely line up with the hole in the tap. Problems rectified with fettling but at that price it is hard to complain.

You will need a 1/4BSP to 3/8 BSP adaptor to go in the tank.

Below is what they look like inside.

Thanks for that Julian.
Is this the kind of adapter required ?  https://www.ebay.co.uk/itm/Bsp-Adaptor-reducer-Male-3-8-to-1-4-Bsp-Female-for-Pneumatics-etc/120806627065?hash=item1c20a2d6f9:g:aboAAMXQfvlSlk8D

[JulianS]

That is the sort of thing.

[hoogerbooger]

have unscrewed the fuel tap & its been soaking in petrol for half an hour. on taking it out no fuel rushes out, but I can see  fuel inside the gauze filter which I can make run back & fore......but it stays inside ?

gauze is more of a yellowy than rusty colour ...... Gummed up ? - will petrol and a tooth brush be enough to eventually remove or is it likely to be gummed up for good ?

[ROYC]

That is the sort of thing.

Thanks , ordered two of each.
Sorry for the off topic.

[Mike Farmer]

 
Hi Julian.

I'm considering swapping my taps over. which taps did you use. Did you need to put collars in??if so what sizes.

Mike

[JulianS]

The mesh filter is usually soft soldered on the original Ewart petrol taps. The filter will come out with use of appropriate heat.

[ChrisG]

Hooger, the original taps are dead simple. You probably have a small piece of errant cork in the vertical hole so you may get away with poking a very thin piece of wire through the gauze without damaging it. Fit new corks but I've used a tip to boil them in water first and it worked for me.
Problem with buying new taps is the British made Brassform (formerly Ewarts) are very expensive at about £34 each so its worth persevering with the original if you can. The lever type are better for accessibility as Julian says and they cost about a tenner plus a 3/8-1/4 bsp bush so about half the price each which is OK if you have the room under the tank, (which you should on the B40) but on the twins its too tight so you need an elbow which makes the total cost not far away from the Brassform.
If you are buying new  lever taps, make sure they have Viton  seal as on the earlier type, the ethanol will make the rubber seal squidgy and the hole closes up rendering you back to square one.
Chris

[JulianS]

I have bough replacement solder in tap filters on ebay from seller  seagullrestorer.

Sold for Ewarts taps fitted to the old British Seagull outboards but fit bike taps as well.

Dont see any on ebay at moment but usually there for about £5 a pair.

[hoogerbooger]

I applied heat to the gauze. This both burnt off whatever was clogging the gauze & burnt off the soft solder. So was able to part the gauze at the previously crimped & soldered end and insert  a bicycle spoke. No cork found but sticky gum removed.

Tap seems now to be unclogged.......but need to re-seal the end. Is there a petrol proof glue I can dip it in  ( araldite ?)or do I need 'soft solder'   ( I have electrical solder- will that do ?...)

Also how do replacement corks attach to my Ewarts plunger...does the brass centre pin unscrew ? ( I had a tentative check but didn't want risk breaking it)