petrol tank taps 1954 G80

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
StephenG80
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petrol tank taps 1954 G80

Post by StephenG80 »

Having put the new carb on - all excited - but then the petrol tank tap starts leaking. It was new off ebay a couple of years ago. Anyhow I take it apart to check it all and then, when tightening it up, the main body deforms including the top thread like putty- basically made from poor quality (I was not playing at being Arnie!). So my question is who sells good quality spare taps (preferable with the ribbed tube where the hose goes on , not plain) that don't leak?

Also whilst I am on, when sitting on the bike is the lh tap reserve and the rh main or VV?

A tad frustrated!

Stephen
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spookefoote1956
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Re: petrol tank taps 1954 G80

Post by spookefoote1956 »

I don't think it really matters as the tank is symmetrical so either side can become the reserve. Some folk like me only use one tap (my new trials tank however has two and I will probably put a blanking plug in it) but others prefer left or right or both.
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Harry44
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Re: petrol tank taps 1954 G80

Post by Harry44 »

I used these their not the "correct" tap but work beautifully.

http://www.ebay.co.uk/itm/Round-Lever-T ... 4d5a892cff
si is does non opportunus vos postulo a maior pango
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thornebt
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Re: petrol tank taps 1954 G80

Post by thornebt »

spookefoote1956 wrote:I don't think it really matters as the tank is symmetrical so either side can become the reserve. Some folk like me only use one tap (my new trials tank however has two and I will probably put a blanking plug in it) but others prefer left or right or both.
I'm sure I read somewhere that the left hand tap is the reserve and that the tank is shaped differently internally so that more petrol remains in that side, although, of course, petrol can slosh from one side to the other. Cheers. Bruce.
alanengineer
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Re: petrol tank taps 1954 G80

Post by alanengineer »

did you soak the corks before you fitted the taps. The taps dont have to bee too tight, just enough to stop them leaking past the threads and washer. And yes, i too have distorted one
StephenG80
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Re: petrol tank taps 1954 G80

Post by StephenG80 »

Hi - after standing I normally soak the corks by switching on till she leaks, switch off for 5 min and then switch on again with re-hydrated corks, no leaks and off we go. On this occassion switched on till she leaked, switched off and she just carried on leaking!!!!! - swore, drained the tank (of course it was full!!!) and dismantled. They are nasty cheapos like these http://www.ebay.co.uk/itm/1-8-Inch-Plun ... Swax5YrsZu. I am not looking to go back to cork.

I am still confused by the reserve tank topic though - if the tank is symmetrical does one side have a column which the tap filter screws into, effectively restricted it from last 1/4 of fuel in the tank?

S
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spookefoote1956
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Re: petrol tank taps 1954 G80

Post by spookefoote1956 »

It stands to reason that if the tank is symmetrical and there is also a tunnel running through it, which there is, that at some point without a hole for the fuel to drop out of then it will stay there until the tap is opened. There again I could be wrong but it sounds plausible.

Cheers, Chris
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
"Creativity is your intelligence having fun" Albert Einstein
56G80S
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Re: petrol tank taps 1954 G80

Post by 56G80S »

But the underside of the tank is not symmetrical, the right hand side (when on the machine) has a larger cut out for the rocker box; from memory.

Johnny B
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Rob Harknett
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Re: petrol tank taps 1954 G80

Post by Rob Harknett »

The left hand side traps petrol on my 55 tank. Easy enough to prove, drain the tank via the RH tap. See what happens when you pull the LH tap on. Expect about 1/2 a gallon to come out the reserve tap. That's what the instruction book tell's you the LH side traps. ( I am quoting the 1955 instruction book. )
Mick D
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Re: petrol tank taps 1954 G80

Post by Mick D »

Hi

I believe both sides of the tank will trap fuel once the level drops below the central tunnel and as neither of my taps has a tube fitted which would make it the main feed I decided to make the LH tap the reserve, for the reason that I don't have to release the throttle to switch it on, (I like my throttle to close when released).

I got my taps from AMC Classic - Teflon seals

Regards Mick
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