The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Amal, Carburation, Fuel => Topic started by: diggerjones on 04.02. 2015 22:12
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Hi all.
Put new plunger type cork parts in my taps a few years ago and new corks. Had afew problems with the taps with them dripping. They leaked when turned off so I didn't turn them off, then last winter it was parked up for a few months , when I started it there was a liquid coming out of the rocker box breather. Anyway the taps had failed and emptied my tank into the engine.
Now to this year and I've done it again, engine full of fuel. At least it gives the engine a good clean *pull hair out* *pull hair out* *pull hair out* *pull hair out* *smile*
Any ideas for the taps, new taps? Rubber of rings instead of cork?
Thanks
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had a similar thing last week, had the tank emptied and the taps out for a good few months, the corks had dried out - petrol everywhere, managed to shove it out the shed at least, and changed the tap plungers with spare I keep in a jar of petrol.
If not immersed or at least in contact with petrol they dry out and shrink, a spare set of plungers with corks fitted don't cost much and if stored in petrol in a sealed jar will stay expanded (actually they will take a good push to get in, good practice would be to change them on a regular basis ( note to self - yes it would)
BTW while on the subject does anybody know the size and thred of the small screw that keeps the plunger in the tap
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Hi,
I tried the O rings advertised as replacements for the corks on fleabay,
Not a total sucess *sad2* fitting the nubber of rings suggested and it pee'd everywhere *problem*
so I added another, then no outside leaks but a dripple through the tap feed and very stiff to boot
When I was on holidays in 2013 with the BSA the petrol in Switzerland caused the cork to fail on the main tap on the SR,
I made a new one from a proper wine cork *work* and its been fine since *good3*
Maybe the corks you fitted were poor quality or not compressed enough?
HTH
John
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So think we are saying, keep taps and get more corks.
Anyone got a link or cork please
Thanks dylan
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Go here for the part number (there are two version)
https://www.draganfly.co.uk/index.php/bsa/bsa/a710--b3133--c101112--m202133/category/955-petrol-taps-pipes
I'd do a bit of googling as these are available from I would think most dealers.
I generally look at Draganfly site as they have a good online catalogue that's easy to use to get part numbers from and I do get some stuff from them and also from many other many traders, so I'm not recommending them over anybody else, I tend to spread my spending over a number of our traders including the guys on here
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I got fed up with leaky cork push pull taps. Try as I might I couldn't get them to seal. I switched to a lever type - which also required an adaptor ring to screw into the base of the tank. Never had a problem since. And I'm pretty sure I got all the bits from Draganfly.
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What I have done as a temporary measure and it works is to fit a suitable washer or washers which are slightly smaller in diameter than the cork and when reassembled it compresses the cork more and thus seals it. I have known this to work for a couple of years.
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Hi DJ,
I also had much the same problem but didn't realise it until I could smell petrol in the oil when I did an oil change. By that time it was too late. Unfortunately the petrol had thinned the oil down so much that within 1000 miles the new camshaft and followers were worn out and had to be replaced. Yeah....a complete engine strip-down causing time, effort and expense.
The decision was made to change the fuel taps to the "lever" type and the problem was solved.
Beezageezauk.
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I have the lever type on the RGF (kept the Ewarts on the Flash as it's kind of stock)
First set of lever type the rubbers swelled and blocked flow (ethanol I guess) second lot work ok but levers have rusted badly, not good on a bike built for Bling *roll*
Don't know if there's differing quality with these, they all look the same
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I use brass ones- I think they're gas cocks, they work fine
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I think that the problem with some of the corks being made today is that they are made from a coarse grade of cork which is really not suitable if the darker sections of the cork run length ways then they are prone to leak. I am going to make some new corks using wine glass cork which is much finer but I have a couple of corks one is all one piece of fine cork perfectly suitable, but the other looks as though it is made up of lots of very small bits somehow stuck together that one I will make the corks up and stick them in a jar of petrol for a while and see what happens.
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Thanks for all the replies, very helpful and maybe a warning to others about petrol getting into the oil and ruining the engine.
So maybe I should get some of these lever type taps. Anyone got a link to some.
Thanks dylan
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I think if you speak to Draganfly they can sort you. Looking at their web site:
https://www.draganfly.co.uk/index.php/bsa/bsa/category/955-petrol-taps-pipes
And within that their note:
BAP type taps are a modern non-leaking tap with 1/4 BSP threads top and bottom, so usually a 1/4 to 3/8 BSP adapter will be required. A nice feature is a locking nut so that the tap can be lined up where it is convenient to use rather than having the lever stuck round the back. The down side is that they do not look anything like the original.
As noted by someone else here I think the lever types can be prone to rusting. Having noted some early onset corrosion on mine I oil them along with all the other brightware every time I clean the bike.
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Thank for your help, will have to have a look,
Rusting will not be a problem, I don't wash it ::hh:: ::hh::
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risking a thread hijack here...
i just tried viton o-rings in the ewarts fuel taps which lists up as 42-8075 being a 3/8" thread tap with bottom banjo. arguably better than the bits of old petrol tubing a found in there (that had cut and blocked the taps) but after starting off well, one week later they are very tight and almost unusable. i'm too lazy for corks not to mention the disasters listed above.
now the question: if i'm reading this draganfly page https://www.draganfly.co.uk/index.php/bsa/bsa/category/955-petrol-taps-pipes (https://www.draganfly.co.uk/index.php/bsa/bsa/category/955-petrol-taps-pipes) correctly my 61 super rocket should have had a 65-8171 lever type like this one: https://www.draganfly.co.uk/index.php/accessories-a-misc/product/13148- (https://www.draganfly.co.uk/index.php/accessories-a-misc/product/13148-). but if the tank fits a 3/4BSP thread then its the wrong tank or the wrong tap...??
anyone know about taps for a 61 SR?
thanks
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another bodge *good3* to get them to seal is to wind some ptfe tape around the piston so the cork is a tight fit over it, this increases the outside diameter of the cork a bit.
Im interested in the home made cork method, I have a ready access to old wine bottle corks *countdown* how to drill the hole and get a smooth outside diameter etc, any tips please?
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Mike,
You are reading Draganfly page correctly but there is a mistake. According to BSA parts cataloque 65-8171s used with TT carbs, 42-8075s with monoblocs.
Markku
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Digger, I had the same problem ,infact i've just found a new set of corks and plungers in my drawer at work. reason being that I was going to use 'em but got fed up with the hit and miss of these taps and decided on a new set from Paul Goff ,excellent quality fitted 3 yrs ago no leaks ,no probs only cost just afew pence over £20 inc postage so can whole heartedly endorse them
www.norbsa02.freeuk.com/goffypetroltaps.htm just checked ethanol proof voitol seal (whatever that is !!) £9.95 each plus £3.95 postage . I have no other contact with the firm except for being a very well pleased customer. cheers BobH
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Hi
Markku is correct,
Super Rocket has banjo type taps, 8075
RGS and goldie use the lever tap, 8171
John
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I found a old brass tap that fitted. But then thought about filters,elbows etc. So ordered more corks, see how I get on. Next winter I will take pipes off if I remember.
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thanks Markku and John
i might go for the lever taps anyway on the SR - give up a bit or original for convenience
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come to think of it.... do the new 42-8075 taps still use cork? some say they are UK made but I don't see this detail listed.
Thanks
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Hi mikeb,
are you shure, you have measured right your tank thread?
3/4"BSP has a thread dia of circa 26,4mm.
Michael
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Probably a typo?
As I said earlier, I use gas cocks that I bought from a gas supply shop, and are much like 65-8171 but without the filter
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Michael - ok lets try that again - 3/8 BSP!
i've now got some 3/8 BSP to 5/16 BSP adapters from a plumber for the new lever taps and will fit them next time the tank is near empty - so i hope they fit!
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I had the same problem so I put the plunger's with the corks attached
in a pot of boiling water for 5 minutes on simmer,
it swells up the corks... & No more drips.. *smile*
Note: do it when the wife is out... *pull hair out*
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Ok. Got new corks. Had them soaking in petrol all week. Now how do you get the corks on the plunger.
Thanks dylan
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on the end of the plunger pull out the pin in the centre of the washer that covers the end of the cork
if that's what you mean or have the corks swollen so much they are tight to push on, I have a spare set of two plungers with corks fitted sitting ready in a jar of fuel.
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Sorry not sure what you mean. I have undone grub screw,took plunger out and pulled/ripped old cork off. The 2 parts I have are a brass plunger riveted to a nurled knob and the tap part that screws into tank.
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The brass plunger is punched out of the knurled part using a suitable pin punch. You can then push a new cork onto the brass plunger, push it back into the knurled part, and re rivet using a small ball pein hammer. This can usually be done 3 or 4 times until the brass piece gets too short to re rivet effectively.
Hope this helps
Arthur
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I think the ones on my RR screwed in, ie; the 'shaft with a head' that goes through the cork, screws into the knurled plunger bit with the notch for the grub screw...??
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The brass plunger is punched out of the knurled part using a suitable pin punch. You can then push a new cork onto the brass plunger, push it back into the knurled part, and re rivet using a small ball pein hammer. This can usually be done 3 or 4 times until the brass piece gets too short to re rivet effectively.
Hope this helps
Arthur
Thanks. That makes sense.
And thanks for everybody's input.
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Some of them have threaded plungers which makes life a little bit easier.
I make new threaded plungers for the rivetted type and tap the knob to suit.
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Not put my taps back yet. But was wondering why I get fuel in the engine, the fuel has to run through float chamber, shouldn't the fuel be stopped when float chamber is full???
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Depends on how good your needle and seat are.
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Not put my taps back yet. But was wondering why I get fuel in the engine, the fuel has to run through float chamber, shouldn't the fuel be stopped when float chamber is full???
Lots of things can go wrong there. The float can be punctured thus not holding up the needle in the seat. The needle seat can be oxidized or dirty or the needle worn.
Does your carb's float chamber have a Stay up float and a Viton tipped needle? They are much more effective than the old type float and flimsy plastic needle
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Thanks for the replies, so we are saying when new this would not happen.