Fuel tank mountings; fuel tap and carb

I now have two Jubilees- both apparently 1961 but quite different. My original blue bike still much like the 50's bikes: Saddle (now restored) still uses the twin rubber bush front mountings. The second (red) has been modified with front mudguard and rear light from a 70's Japanese bike- probably a Yamaha. The saddle hinges up towards the rear. This bike also lacks the "choke" air slide control present in the "earlier" model.

Tank Mountings:
Both bikes seem to have muddled tank mounts. The tank is mounted onto a rubber bush at the front, but the rear is bolted to the frame using a weld nut positioned on the underside of the frame lug. The bolt should be cushioned with rubber washers, but in my case the blue bike was fitted with a pile of grommets and petrol pipe, whilst the red had some large degraded rubber washers fixed on top of an old wheel bearing!

By pooling both bike parts I could assemble a set of the correct mountings  for one bike, however rubber washers were all damaged, perished or absent so I bought new rubber washers from NOC.

From left to right (and bottom to top in position): Top hat rubber washer, steel collet, top flat washer cover washer and bolt/washer. The top hat washer fits at the bottom on top of the frame with the collet inside. The projection fits through the tank rear mounting eye with the flat washer on top and the cover washer on top of that

 The collet fits inside the top hat washer and prevents this from being crushed as the through bolt is tightened. The bolt could be screwed into the weld nut of the blue bike.

Tank rear mounting eyelet. Weld nut positioned under the hole in frame below

In the red bike the weld nut on the frame lug had been drilled out to allow a through nut and bolt to be fitted anchoring the pile of wrong fittings that secured the tank in this bike. Since the weld nut had been enlarged a new bolt would be no help and as this is already a non standard bike I simply tapped through the frame weld nut to M10 and then fitted an M10 shoulder bolt cheaply available from Ebay.

New rubber washers as above and M10 shoulder bolt

 It was necessary to enlarge the holes in the rubber washers to accept the shoulder  and as the shoulder in this bolt was slightly too long, I reduced the length of the shoulder by turning the shaft down to the width of the threaded section. This allowed the sbolt to fit lower, so that the shoulder just fitted on top of the frame when tightened. Since the M12 shoulder cannot pass through the M10 weld nut, it is not possible for it to compress the top hat washer and so the internal collet is no longer necessary.

Original bolt (right) and turned bolt (left)

Weld nut tapped to M10 and top hat washer inserted below tank eyelet. The pic suggests that the holes don't align but in fact the tank can easily be pushed forward on the rubber bush to align the holes.

Tank rear mounting

Tank fixings in place.

Carburettor
Bike number one was fitted with the air control (choke) on the bars and the cable connecting this to the slide mechanism inside the carb. The second bike had no cable or control, the internal parts of the choke were missing and the cable entry on the carb top was sealed with insulating tape! I could restore the slide mechanism and cable plus control as all parts are available but this would be expensive. Furthermore the air slide is not particularly effective anyway and starting is usually done using the tickler. Its even possible that these later '61 bikes  had no air slide fitted? In any event Amal sell a plug bolt to seal this cable hole suggesting that the air choke system isn't always fitted.
I bought the correct screwed plug from Burlen and also the clip that secures the top retaining ring. Sadly there was some problem with the plug supplied and it didn't fit the carb top. I therefore tapped the carb top to M6 and inserted a standard M6 bolt to blank off the hole. The clip was fitted using the new M6 bolt and the central screw.

Modified Carb top: Note throttle cable on left, central fitting screw and new bolt plug inserted into the unused choke cable hole. Screw and bolt used to secure retaining clip.

Fuel Tap
Bike no 1 was fitted with a plunger type Ewarts tap which worked well. The more modern bike had a very stiff brass tap as shown.

Brass fuel tap, this position is actually "on"

I don't know if this is an original tap but there were several issues with it. Firstly the tap positions were counter intuitive; the tap being in the "on" position when it was fitted across the outlet and "off" when in line. This is the opposite to the usual convention.
Secondly-if the fuel tap was left "on" without running the bike this lead to carburettor flooding and loss of fuel through the overflow. This suggests that the float valve in the carb may need attention as well.

New fuel taps are available from the NOC (although very expensive). Investigation showed that the tank body is threaded as 1/8 BSP and there are few petcocks of this size available in the UK, most bikes using a 1/4 BSP. However simpler taps are readily available from eBay and far cheaper! The tap below was purchased for just £2 from eBay.

This tap (which even comes with a top fuel filter and settling bowl) is threaded M10 1.25 and will not screw directly into the tank. Fortunately a 1/8BSP to M10 1.25 adapter is available from Venhill as a brake system build part for £5 and this works well to allow the new tap to be fitted.

Venhill 1/8bsp to M10 1.25 adapter

Being a brake part its sized for a flared fitting internally but this can be easily drilled out a little wider

The 1/8bsp section was drilled right through the fixture to 4mm (the diameter of the original tap pass through passage) and then enlarged internally to 6.6cm but to a very shallow depth (3mm) so it could be tapped to M7. This allowed the fuel filter  that came with the tap to be screwed into the top of the adapter before this was screwed into the tank, and then the tap body could be screwed into the M10 socket in the base. Fibre washers were included above and below the adapter to provide a fuel-tight seal.


Carburettor Float valve

Carburettor viewed from float chamber (bottom), note tickler button  centre, and fuel inlet banjo on right

The fuel inlet banjo and intake filter were removed by unscrewing the small top bolt (left in pic above) to remove the banjo union. I knew that the PO had renovated this carb and replaced the filter only recently so I was surprised to find it already dirty. I guessed that this muck might be blocking the float valve which was therefore also removed and cleaned although no contamination was evident. The float needle had already been replaced with a Viton tip and the float was fitted correctly and showed no sigh of leaks.

However, removing the banjo (above) also showed that there was a fibre washer beneath the float valve housing seen in picture above to the right of the tickler button. This was apparently a metric sized washer that was a poor fit over the threaded spigot. In fact no washer is shown in this position in the Amal diagrams, and one is fitted there only to "later" carbs. In fact this position is used to adjust fuel height with shims so it seems that the use of a washer where none is usually needed would lead to a raised fuel level in the float chamber. This could also be the cause of the overflow I had suffered. Accordingly I removed this washer when the carb was reassembled. I will also include an in-line fuel filter since there does seem to be a problem with sediment coming through from this tank, however the tap filter, settling bowl and in-line filter should control this in future.

 

Clean fuel filter

Float and needle reinstalled once needle housing has been replaced without the fibre washer

Banjo reinstalled using new fibre washer beneath retaining bolt.

Norton Jubilee Front Wheel and Brake

The removal of the front wheel and the structures I found on the axle/spindle are described at the start of the entry "Refurbishing the front forks..."


On the credit side the front tyre as fitted to this bike looked fine! However the front brakes are  poor to non-existent and tended to jar in use. I had already removed the front wheel and this is what I found...

Oil seal enclosure visible in hub, there should have been a separate spacer in the centre of this seal, Bearing grease looks bad, they felt rough. . Inside of hub quite rusty

 This bike was a surprise in terms of hub oil seals, instead of the expected rubber or nitrile lipped seal, the bike uses a system of felt washers held within an enclosure formed by a recessed washer into which the felt fits and a backing washer that provides pressure forcing the felt into contact with the axle spacer.. The top of the recessed washer of this felt enclosure is visible in the hub centre, and the oil seal could be pulled out with a slide hammer - which I did at this stage although in hindsight it would probably be preferable to drive it out with the bearing at a later stage.

Internal hub felt seal, Felt housing on left and backing washer on right. Note remnants of felt washer  inside the housing- clearly deteriorated and serving no useful purpose at all!

On the reverse of the hub itself there was a domed cover which retains a second oil seal enclosure.

Domed cover (left) and oil seal enclosure (right). This seal had no felt and no backing washer. Instead a more modern nitrile/rubber seal had been installed in the enclosure.

The seal on the hub exterior was a surprise in that the inner washer to the housing was missing and the felt itself had been replaced with a more modern oil seal. However this had not fared well, it was badly damaged and distorted. I need to consider how best to replace this. The cover plate (above) is from a pre 1961 style front wheel; these had a felt oil seal and two part enclosure on both sides. There was also (as in this case) a separate spacer on the spindle that penetrated and sealed the oil seal around the axle. However both of these features were changed in 1961 when the front axle was redesigned to a knock through rather than a drop-out format. The solid axle was redesigned on the rhs as was the brake plate retaining bolts and these were as found on my bike. It seems therefore that this bike has a 1961 design on the right hand side up to and including the rubber/nitrile oil seal in its enclosure on the lhs. However after that the parts have been substituted for those from a pre 61 bike with separate spacer and cover although the locknut was missing. This doesn't seem to be adequate to fix the wheel in the right position laterally between the forks and will need further investigation on reassembly.

Brake backplate, some signs of grease escape, brake shoes scuffed. Note combination nut-and-spacer in centre which fits into the felt oil seal in the inside of the hub.

I decided to strip and clean the brake mechanism and replace the bearings and oil seals. The first step was to remove the brake back plate from the front plate. This is held on by a large nut and this component puzzled me for a while as its not shown in the parts list. However it seems to be a replacement for two separate parts and effectively combines the nut with the spacer that fits into the hub oil seal.

Brake plate fittings, combination nut-and-spacer and external nut removed all according to the post 61 design.

Remove the brake shoes by bending them upwards- these springs seem very strong!

Once these were removed the brake backplate was still attached to the painted front plate by the operating lever. There is a small spacer between the two plates.

Brake shoes removed. Note two small shoes (slippers) for the operating levers-presumably to prevent wear in the softer shoe heels where they bear on the steel operating lever- unusual, I've not seen that before!

Brake lever components detached

The brake lever was a little awkward to remove, I held the external nut downwards in a vice and turned the operating pivot with a pair of grips to unscrew it. Here the components are laid out. There is also a square cut washer beneath the brake lever which prevents it jamming on the hub in use. This washer hasn't yet been removed from the spindle.

Brake operating pivot components removed and cleaned. Note spacer from between the plates (top row) and the square section washer removed from the brake arm pivot (bottom row)

Smear of copper grease on operating spindle

The complete set of components are here removed and cleaned with a wire brush. There was some corrosion on the operating lever pivot which wire brushed off. The hub front and back plates were reattached using the "combi" spacer-nut system remembering to include the spacer between the two plates

Operating lever pushed through backplate. Don't forget the square section spacing washer before refitting the arm, top washer and nut

 and on the slipper plates to stick them onto the operating pivot whilst...

another blob is applied to the top of the slipper plates in contact with the shoes.

before positioning the shoes as above and folding them down. Note that their feet will probably need to be levered up slightly so that they click into position as the shoes are flattened.

 I haven't yet changed the brake shoes, although these are scuffed they do not seem to be contaminated and there is plenty of material left on them. I will give these a chance to "bed in" and hope they will improve with use. If not then new shoes will be needed. Although its not shown here I also cleaned and degreased the inside of the hub drum with wire wool and methylated spirit.

 Bearing and Oil seal replacement

Front wheel bearings in this bike were originally of the open type. This requires an efficient oil seal to retain grease so I decided to upgrade to sealed bearings which do not require free grease and are therefore more tolerant of poor oil seals in the the hubs themselves. I decided to use the original felt washer enclosures so that all the spacings and clearances should be maintained. However, I havent yet decided whether to use these with the original felt washers or to use a more modern equivalent. The washers are not available precut so I ordered some 8mm oil seal felt to cut my own and I also ordered some narrow oil seals (24x36x6 Simplybearings.co.uk) which might also fit into the housing. However, bearing in mind the poor condition of the seal removed from the left had side of the wheel, I think its necessary to include both parts of the enclosure and so I needed a new flat washer base. These are also no longer available but fortunately 32 mm penny washers are still readily available and so I bored one out so that it would slip over the spacer in the axle. I will test the two systems to see which is most likely to work. (Note I have since found the felt washers listed in the Norton Owners Club shop.)

The bearings were an easier replacement as they are still available as 6202-2RS (35, 15, 11 mm) and I bought two made by SKF from bearingboys. The bike has a bearing on each side and a tubular spacer in between. Removing the bearings is simple, I knocked the out from one side using an old screwdriver drift which engaged nicely with the bearing spacer junction.

Using a drift to knock the bearings out from above- note support hub on wooden blocks. 

Later I discovered that the manual suggests  to knock the bearings and seals out together using the bare axle- probably a better idea!

Inner bearing removed- end of spacer visible inside hub

Spacer lifted out- nasty gunky thing!

 The opposite bearing was then easily drifted out from the other side. The new bearings were easily tapped into the hub (I used a Bergen motorcycle bearing set). Interestingly one of these was loose and tended to drop out. This is a little ominous and I'm hoping it doesn't indicate out-of-round. However it was a reasonable sliding fit so I secured it using Loctite 603 (oil tolerant).

Tapping in bearings using Bergen drift set.

Oil Seals
I'm not sure what to do about the oil seals, having made a new backing washer for the enclosure I could replace the felt seals both sides. However this seems to need 8 mm felt as the 5mm that I have isn't compressed in the housing. The alternative is to use more modern shaft seals, although the fate of the previously installed example suggests that they shouldn't be used without the base washer. I bought two 24x36x6 mm nitrile rubber rotary shaft seals R21/SC from simply bearings. These fitted nicely into the  cupped enclosure washer although they were a little too thick.

Seal as above and enclosure washers, the seal was pressed into the washer easily with hand pressure.

Fit the flat washer first... at this stage I felt that this had been lost from the wheel and so I made one up to replace it. However, I have now discovered that a rubber seal should be fitted without this inner washer and that may explain why the hub later proved problematic on assembly.

Then the oil seal in enclosure and tap home

The oil seal fitted well and might work...? I am slightly concerned that it doesn't seem to clip into place and the whole housing seems to rotate whereas usually one side of the seal would be held stationary, however I can't yet tell if this will stop when the wheel is reattached. Secondly an oil seal wouldn't usually be compressed, but here as it is thicker that then the enclosure is deep* its likely that it will be under some pressure if indeed the extra width of an oil seal on both sides doesn't prevent me from fitting the wheel back in the forks!  I wont be able to tell this until I have finished the fork repair and refitted the sliders. Lastly an oil seal would usually have grease on at least one side to provide lubrication. The new bearings don't require free grease and the seals here are really only to keep the dirt out of the wheel rather than contain oil/grease in the hub, however I will put some grease below the seals for this purpose.
* this may well be because at this stage I had fitted an inner washer which has prevented the seal from seating properly.
I have ordered some 8mm felt and will prepare some thicker felt washers so that I can try both systems.


Once the forks were repaired I was able to fit the wheel. Here I found that the internal oil seal fitted inside the hub (brake plate side) worked well, it assembled and fitted well. However the excess thickness on the seal caused problems on the left side of the wheel. Here the thick seal prevented the seal enclosure  (dished washer) from seating into the hub centre. Since this didn't seat, the external cover could also not clip onto the wheel and was left loose and spinning when the wheel was tight in the forks. To cure this I had to remove the oil seal and reassemble this side using the felt washer seal instead. I oiled the felt and the seal retainer now clipped into the wheel hub and the dished cover clipped firmly over that.

Jubilee Seat Recover

Having fixed the pan, bought the new foam and returned the ill-fitting cover received from Ebay I ordered a new cover from the owners club. I had to wait a while for this but when it came it was a much better fit- in particular the inner flap was much deeper towards the rear of the seat allowing it to fit over the pan sides which are deeper at that point. Before I fitted the cover I inserted the new seat rubbers into the new mounts I had made at the front and also put two new rubber buttons into the button mount pads on the base. Silicone spray helps when fitting these parts.

Seat pan rubber components installed.

 I then checked that the pan fitted the bike, Its no use fitting the cover if any more welding might be required! Luckily with minimum adjustment it fitted well. Note metal of pan doesn't contact the tank.

Well... this is how I fitted the cover- and I'm pleased with the result but bear in mind I'm not a trimmer so this might well not be the "right" way at all. Firstly I laid the cover on a soft pad to avoid scratching it, then I fitted the foam and pan on top and pulled the cover around roughly - you can see the wider side panel in the picture and how it now covers the pan sides. It is worth while spending time here to make sure that its positioned evenly around the seat.

Seat cover roughly in position

I used these clips from Woolies, sold in packs of 10 I needed about 25 to fit the cover.

I then stretched to cover to align the white beading with the bottom of the seat pan. Note that the inner flap folds over the metal seat edge, the white beading is effectively "hanging" and covers the clips. This design avoids the use of beading to edge the seat which would be difficult for this one owing to the pan design at the rear. Its hard to stretch both sides at once so I secured the left side with a clip as above but pushed on only finger tight so that I could reposition it if necessary. I could then stretch the seat cover to align the white beading on the other side.

Securing one side first with a finger tight clip, not that the inner flap only is secured, the white beading is free.

Stretching the fabric to align the beading on the other side

I then fitted the second clip by hand pressure- checked alignment both sides and then secured the clips on both sides by hammering them down. Fold the white beading flap out of the way while you do that. I then stretched the cover into place- aligning the beading with the seat edge around the back. I secured the rear of the pan first with a clip each side of the join in the fabric at the back, and then pulled it over the horizontal strengthening panels at the rear of the seat- again securing with clips.

Clips at rear of pan

 I Continued to stretch the seat cover into position adding clips along the sides until I got to the front where the seat cover projects over the pan as shown. Make sure that the flap fits down well beside the rubber seat bush holders- if necessary cut it so that it fits smoothly.

Front of seat

Folding the front section

I folded the front overlap around the seat edge - it was bit bulky so I removed some of the flap (not the front section with beading which I didn't cut at all) so that the material would fold more neatly.

Once it folded nicely I secured the front of the seat using a clip on the vertical edge of the seat pan.

Clip on vertical side

I repeated the process on the other side before securing the excess flap material around the seat with adhesive.

This is the glue I used (Vitrex), you spray it on both surfaces to be stuck, allow time for it to dry and go tacky and then stretch and press the surfaces together. I peeled up the fabric below the clips and sprayed the inside of the fabric and the metal seat pan with the glue. It is essential that you wait for it to dry on both surfaces- do not be impatient. I already knew this but even so I still ended up trying to stick them too soon- so give it the time. The can says 2 min but I'd say at least 5 and maybe longer.
Also- be warned! The glue is really sticky and will reduce your hands to useless claws! Keep the white spirit handy!

Peel up fabric and spray underside and metal below

 Ease the fabric down onto the glued metal and stretch it neatly into place. You will need to cut slots so that it fits around the the button supports on the pan base. Fit and stick the fabric under the strengthening sections at the rear. Glue all sections of the fold at the front- note this is a multilayered gluing process which proved a bit too much for the glue's instant grab. Its probable that a more confident fitter would have cut the front flaps more accurately and got a better fit. I didn't want to risk making any holes in the cover so I cut the very least off that I could. To help the bond form I clamped both sides and left them for 24 hours.

Clamping the front folded section into place so that the glue can bind. Note foam projecting at front of pan.

 Note that having fitted the cover over most of the seat, the foam projects about an inch over the front of the metal. I'm not altogether sure whether this is a problem with the size of the new metal I welded in or if (as seems more likely) it allows the foam to fit closely against the tank without scratching it.

 The final step was to glue the underside of the front flap and pull that tightly across the front of the foam and the metal base, pressing to secure it. Finally I placed the seat back on the bike (its not fitted- just resting there) for all the glue to set properly, clamps in place.

...And finally fitting the thing properly...

Finished seat fitted in position

 

And the seat before attention- like sitting on a flatulant jellyfish

New cover from rear- beading join isnt pretty but its in the cover.

... Now all I have to do is fix the rest of the bike!!