Classic Petrol Tap

Post Reply
GeoffD
moderator
Posts: 17
Joined: Mon May 23, 2016 1:31 pm

Classic Petrol Tap

Post by GeoffD » Mon Jul 20, 2020 12:08 pm

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

johnbirchjar
moderator
Posts: 1410
Joined: Sat Mar 07, 2009 11:20 pm

Re: Classic Petrol Tap

Post by johnbirchjar » Mon Jul 20, 2020 11:13 pm

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 evil)
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 Very Happy(even the "reserve" on the vac tap wink)
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 evil ,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
moderator
Posts: 1410
Joined: Sat Mar 07, 2009 11:20 pm

Re: Classic Petrol Tap

Post by johnbirchjar » Tue Jul 21, 2020 2:53 pm

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 cool.
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 wink) ethanol proof for the past six years and umpteen thousand miles Very Happy,SVF,J.B.

GeoffD
moderator
Posts: 17
Joined: Mon May 23, 2016 1:31 pm

Re: Classic Petrol Tap

Post by GeoffD » Wed Jul 22, 2020 11:01 am

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
Site Admin
Posts: 189
Joined: Sun Aug 11, 2013 8:13 am

Re: Classic Petrol Tap

Post by Anthony Duffield » Wed Jul 22, 2020 8:13 pm

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
moderator
Posts: 1410
Joined: Sat Mar 07, 2009 11:20 pm

Re: Classic Petrol Tap

Post by johnbirchjar » Wed Jul 22, 2020 11:04 pm

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 smiley)and I believe that the "Prime" on the fuel tap by-passes the vac system,not 100% sure though,SVF,J.B.

GeoffD
moderator
Posts: 17
Joined: Mon May 23, 2016 1:31 pm

Re: Classic Petrol Tap

Post by GeoffD » Thu Jul 23, 2020 8:03 pm

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
moderator
Posts: 1410
Joined: Sat Mar 07, 2009 11:20 pm

Re: Classic Petrol Tap

Post by johnbirchjar » Thu Jul 23, 2020 10:32 pm

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.

User avatar
Richard Negus
moderator
Posts: 999
Joined: Mon Jun 18, 2007 5:11 pm
Location: Wilds of Lincolnshire

Re: Classic Petrol Tap

Post by Richard Negus » Fri Jul 24, 2020 5:53 pm

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.
Slower slower, no faster faster - the joys of old fogey mode to hooligan mode at the flick of a switch

holger999
moderator
Posts: 82
Joined: Fri Jun 13, 2014 5:22 pm

Re: Classic Petrol Tap

Post by holger999 » Fri Jul 24, 2020 6:37 pm

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

User avatar
Richard Negus
moderator
Posts: 999
Joined: Mon Jun 18, 2007 5:11 pm
Location: Wilds of Lincolnshire

Re: Classic Petrol Tap

Post by Richard Negus » Fri Jul 24, 2020 6:51 pm

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.
Slower slower, no faster faster - the joys of old fogey mode to hooligan mode at the flick of a switch

johnbirchjar
moderator
Posts: 1410
Joined: Sat Mar 07, 2009 11:20 pm

Re: Classic Petrol Tap

Post by johnbirchjar » Fri Jul 24, 2020 10:40 pm

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? wink,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
moderator
Posts: 105
Joined: Fri Jul 20, 2007 5:45 pm

Re: Classic Petrol Tap

Post by Ian » Sat Jul 25, 2020 8:24 am

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
Site Admin
Posts: 189
Joined: Sun Aug 11, 2013 8:13 am

Re: Classic Petrol Tap

Post by Anthony Duffield » Sat Jul 25, 2020 11:30 am

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
moderator
Posts: 1410
Joined: Sat Mar 07, 2009 11:20 pm

Re: Classic Petrol Tap

Post by johnbirchjar » Sat Jul 25, 2020 10:55 pm

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
Site Admin
Posts: 189
Joined: Sun Aug 11, 2013 8:13 am

Re: Classic Petrol Tap

Post by Anthony Duffield » Sun Jul 26, 2020 10:03 am

John,

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

Tony

mickm
moderator
Posts: 102
Joined: Thu Feb 24, 2011 3:15 pm

Re: Classic Petrol Tap

Post by mickm » Sun Sep 27, 2020 4:11 pm

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
moderator
Posts: 69
Joined: Mon Feb 15, 2016 9:26 pm

Re: Classic Petrol Tap

Post by cdrkeith » Sun Sep 27, 2020 6:13 pm

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
moderator
Posts: 102
Joined: Thu Feb 24, 2011 3:15 pm

Re: Classic Petrol Tap

Post by mickm » Sun Sep 27, 2020 6:55 pm

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

User avatar
Richard Negus
moderator
Posts: 999
Joined: Mon Jun 18, 2007 5:11 pm
Location: Wilds of Lincolnshire

Re: Classic Petrol Tap

Post by Richard Negus » Mon Sep 28, 2020 9:28 am

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.
Slower slower, no faster faster - the joys of old fogey mode to hooligan mode at the flick of a switch

mickm
moderator
Posts: 102
Joined: Thu Feb 24, 2011 3:15 pm

Re: Classic Petrol Tap

Post by mickm » Mon Sep 28, 2020 2:04 pm

thanks Richard a mine of information as ever. Mick

johnbirchjar
moderator
Posts: 1410
Joined: Sat Mar 07, 2009 11:20 pm

Re: Classic Petrol Tap

Post by johnbirchjar » Mon Sep 28, 2020 11:18 pm

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 evil,J.B.

mickm
moderator
Posts: 102
Joined: Thu Feb 24, 2011 3:15 pm

Re: Classic Petrol Tap

Post by mickm » Wed Sep 30, 2020 8:36 pm

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

User avatar
Richard Negus
moderator
Posts: 999
Joined: Mon Jun 18, 2007 5:11 pm
Location: Wilds of Lincolnshire

Re: Classic Petrol Tap

Post by Richard Negus » Wed Sep 30, 2020 10:16 pm

johnbirchjar wrote:
Mon Sep 28, 2020 11:18 pm
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 evil,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.
Slower slower, no faster faster - the joys of old fogey mode to hooligan mode at the flick of a switch

Assen
moderator
Posts: 122
Joined: Mon Apr 21, 2008 5:47 pm
Location: Assen Netherlands

Re: Classic Petrol Tap

Post by Assen » Sun Oct 04, 2020 3:16 pm

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
moderator
Posts: 102
Joined: Thu Feb 24, 2011 3:15 pm

Re: Classic Petrol Tap

Post by mickm » Mon Oct 05, 2020 8:56 pm

Assen wrote:
Sun Oct 04, 2020 3:16 pm
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.

Post Reply