Classic Petrol Tap

[GeoffD]

Has anyone found an alternative (non vacuum operated) petrol tap to suit the Classic ?
Ta.

[johnbirchjar]

Yep,I fitted one on my Classic about 6 years ago,(I got fed up replacing the diaframes being eaten by the p**y ethanol )
I left the vacume tap in position(1st removing the diafram)and then just putting a regular on/off tap twix the vac tap and the N/side carb:It has worked just fine ever since (even the "reserve" on the vac tap )
The one "down side" was having to remember to turn the on/off tap to "off" if not using the bike for a week or more('cos I have been led to believe that the SU carbs would sometimes let petrol seep into the chambers ,hence Nortons fitting the "vac" tap)The other slight drawback was not enough room fit an extra fuel filter,(should the one in the vac tap that goes into the fuel tank become damaged)
I am sure "Keith" who bought my Classic from me would send photo's if asked nicely,SVF,J.B.

[johnbirchjar]

Further to last nights post,
Keeping the original vac tap in place and putting a standard on/off tap twix vac tap and n/side carb meant that the fuel tank could be removed without having to drain out all the fuel .
I didn't remove the diafram completely,just the little tension spring,left the diafram in place 'cos it acts as a gasket,with just a thin smear of gasket glue which has seemed to be(fortunately ) ethanol proof for the past six years and umpteen thousand miles ,SVF,J.B.

[GeoffD]

Thanks John.
I was thinking along similar lines myself, re fitting an intermediate tap.
I've not had a problem yet, although I do worry about the vacuum tap leaking when stood for long periods.
The other issue is that if the bike has been stood for a while and the fuel has evaporated from the carbs, you have to wait for the vacuum tap to eventualy "wake up" and start supplying fuel.
Ta, Geoff.

[Anthony Duffield]

John/Geoff,

I hope I am not tempting fate but I have not experienced any issues with the fuel tap, either leaking or the issues of the carbs drying out

Perhaps I have just been lucky

Tony

[johnbirchjar]

Hi Geoff,
Never in 30 years or(70,000 miles)did I have a problem with the carbs drying out,mind you,the bike never stood for any length of time even in the winter,there always seemed the odd day that was nice enough for a spin(we don't seem to get bad winters in my part of Essex )and I believe that the "Prime" on the fuel tap by-passes the vac system,not 100% sure though,SVF,J.B.

[GeoffD]

Thanks for the replies guys.
I guess I'm just being paranoid about the tap.
Interesting point about the "prime" position though, I just have the two position on my tap - pointing down for "main" and pointing forward for "reserve"
Regards, Geoff

[johnbirchjar]

Hi Geoff,
The tap you have is the later one,the earlier ones had three positions,Reserve on the left,On straight down and Prime on the right,(I have no idea why Nortons changed the taps from three to two positions,supply?)any idea which model was/is fitted to Commander's and the F1 models?J.B.

[Richard Negus]

Early IP2's had a simple on/off mechanical tap on the left and a three-position vacuum tap on the right.
Many engines failed because plod riders didn't turn the l/h tap off at the end of the day and as fuel evaporated from the hot float chambers, more fuel was allowed in. The evaporated fuel ended up in the engine, washing oil off the side faces, and allowing the seals to score the plates next time the engine was started.
Norton's solution was to remove the l/h tap and fit a blanking cap in it's place. Problem gone away? No!
The vacuum tap's 'prime' position bypassed the vacuum part of the tap, allowing unrestricted fuel flow to the carburettors.
Again plod riders sometimes left the tap in the 'prime' position giving the same failure as above
Norton solution was to laser-cut a new lever plate, restricting the tap to only 'on' or 'reserve', both controlled by the vacuum fuel valve. Problem gone away. Mostly.
Then along came E5 fuel, not a twinkle in any petro-chemists eye when these taps were built by Mikuni. E5 contains 5% alcohol and is very good at attracting water which attacks the working seat of the vacuum valve. Hence the valve leaks a continuous small amount of fuel. Solution? New tap!

As the taps were originally bought direct from Mikuni, there's no cross-reference to what machine it was originally built for.

F1and F1 Sport taps are 'borrowed' from a Yamaha FZ750, about 1987/88 vintage.

The only difference between an IP2/Commander fuel tap and a Classic tap is that the latter was modified by Norton to have it's outlet pipe on the other side of the tap body to suit being fitted on the left side of the fuel tank.
Logic for that was to allow the rider to switch to 'reserve' when the engine coughed without letting go of the twistgrip. Discuss.

[holger999]

https://www.ebay.de/itm/KR-Benzinhahn-Y ... 2810086571

hello Richard,

is the type of petrol tap correkt? for my F1 Sport?

best regards
Holger

[Richard Negus]

Hi Holger,
I don't have a cross reference by part number, but that one looks to be correct for F1 and F1 Sport.
The original Yamaha part number is 26H.24500.00.
R.

[johnbirchjar]

Hi Richard,thanks for the info:
Although I still can't see the logic of having petrol taps on both sides of the tank,when a three way one on the n/side(as per Classic's) seems logical 'cos when one requires the reserve ones right hand can still be on the throttle.
OK, I suppose a lot of it was what Nortons could purchase,but why two taps?unless the tank was in two halves on the IP2's? ,but then again am I correct in thinking that the reserve on Commanders cannot be turned on when traveling 'cos it is behind the bodywork?J.B.

[Ian]

You're right about the Commander fuel tap John.

Norton had a moment of brain fade by putting the fuel tap on the right side, so you couldn't easily use it when riding anyway, then rubbed it in by making sure you had to remove the bodywork to get to it, thus guaranteeing a roadside stop!

I'd love to meet whoever signed that off!

Incidentally, I leave mine on reserve and use the trip and the gauge. Probably wrong but it's worked for me for 25 years!

Ian

[Anthony Duffield]

Thank you Richard for the interesting info concerning the lever plate, restricting the tap to only 'on' or 'reserve', both controlled by the vacuum fuel valve.

I have only once run out of petrol when in the IoM, coasted to the side of the road, less than 5 mins to switch to reserve and away again, I carry a stubby screwdriver in my pocket for such emergencies.

I get such a lot of enjoyment from owning and riding my Commander little things like a hidden fuel tap do not bother me too much.

[johnbirchjar]

Hi guys,am I the only one that has had problems with etanol eating the diaframs on the vac: fuel taps?and again, has anyone done the "conversion"with the vac: taps on a Commander? (they look different on the F1's)J.B.

[Anthony Duffield]

John,

So far no issues with ethanol, neither Commander or 650 SS

Tony

[mickm]

the IP11/Commander petrol tap look's the same as the Classic!! and is in stock at A.N. can anyone explain why it isn't Please.

[cdrkeith]

From Richard Negus' post of Friday July 24th, above -- last para:

"The only difference between an IP2/Commander fuel tap and a Classic tap is that the latter was modified by Norton to have it's outlet pipe on the other side of the tap body to suit being fitted on the left side of the fuel tank.
Logic for that was to allow the rider to switch to 'reserve' when the engine coughed without letting go of the twistgrip. Discuss."

Is that your answer ?

[mickm]

Thanks a Richard, So I can use a IP11 / Commander tap on my Classic? Mick

[Richard Negus]

Mick,
You can use the IP2/Commander tap 92.1783 on a Classic, but the fuel outlet stub will point forwards instead of backwards. It will need a longer fuel pipe, which doesn't look so neat, but that gives you the opportunity to fit a proper paper-element filter - always a good move.

You could, of course, dismantle the new tap, pull out the outlet stub and fit a plug, and then drill the other side of the tap to re=fit the stub pointing backwards. Plug and stub are fixed with Loctite 648. Use compressed air to blow out all the swarf before re-assembling it.
R.

[mickm]

thanks Richard a mine of information as ever. Mick

[johnbirchjar]

Just as a point of interest Mick,why on earth would you want to put a Commander/IP2 tap,on your Classic?especially as they face the wrong way ,J.B.

[mickm]

Put in stock Just in case
On another sunject. AN now have new rear chain gaiter £48 each +vat &p&p

[Richard Negus]

Just as a point of interest Mick,why on earth would you want to put a Commander/IP2 tap,on your Classic?especially as they face the wrong way ,J.B.

'Cos the correct Classic tap is not available and, as has happened on several occasions, water in the fuel corrodes the shut-off seating face in the tap body and it leaks fuel to the carburettors when the engine is stopped.
With only 100 bikes in the market and many not being used, Andover Norton are most unlikely to convert a few IP2/Commander taps to make Classic ones.
R.

[Assen]

Just bought another bike. An Yamaha SR500 from 1980 from it's first owner. 10.000 miles. As it had stood for a while, the petrol tap started leaking as soon is i put petrol in the tank. So i bought an petrol tap overhaul set from Yambits. Looking at the new parts they looked exactly the same as my Classic petrol tap insides. So i mesured things and it turned ou that indeed the yamaha parts fits the petrol tap from my Classic without any modifications. Good news i guess?
So if you need parts, go to "Yambits" and search for; Fuel tap repair kit for a SR500 1978-1981, It's 19,90 Pounds.

Jannes

[mickm]

Just bought another bike. An Yamaha SR500 from 1980 from it's first owner. 10.000 miles. As it had stood for a while, the petrol tap started leaking as soon is i put petrol in the tank. So i bought an petrol tap overhaul set from Yambits. Looking at the new parts they looked exactly the same as my Classic petrol tap insides. So i mesured things and it turned ou that indeed the yamaha parts fits the petrol tap from my Classic without any modifications. Good news i guess?
So if you need parts, go to "Yambits" and search for; Fuel tap repair kit for a SR500 1978-1981, It's 19,90 Pounds.

Jannes

That’s good news thanks. Every little bit helps.
Mick.