Weepy Electra Primary side filler cap

Hi Peter, I am very lucky, they are a real joy and worth the hard work getting them in acceptable fettle and keeping them that way!    As for the sealing washer - dooooh, I usually check Norvil and Andover for spares if the club don't have them but for some reason I assumed they were unavailable.   Whilst the rubber O ring obviously works for some they just don't quite work for me - particularly on a long and spirited run which the Electra seems to attract!   I have ordered 4 so I have some in stock - 'just in case'!    I hope your Electra is in good form and you have time to enjoy getting out on it in this glorious summer weather!   

All the best

Nick
       

Thanks Ian, I haven't done anything cosmetically since I got the Electra because whilst not perfect it was as you see it, including the clever little tool bag which happily doesn't rest on the rear mud guard which can cause them to fracture.   
In the last two years I have had to replace the right hand cylinder head which had a long history of leaking oil despite replacing all the gaskets.  Eventually I narrowed it down to a porous casting.   Right hand heads are like hens teeth but luckily Andy S pointed me in the direction of someone who had a NOS unused bare head which motivated me to do a full top end overhaul including new valves, guides, cam followers and guides and a light hone of the bores and new rings. 
I use Peter's top tip of using two gaskets to each rocker box and religiously torque down the heads regularly when running it in.   This spring I did a gearbox, clutch and starter deep service and rebuild to improve some of the gear selection and starter issues.   Amongst other horrors I found the bolts on both ends of the gearbox main shaft loose, the kickstart shaft pawl hole so badly warn that the pawl was sticking, a stripped thread on a gearbox cover retaining screw and a broken starter pawl pin.   61 years of home maintenance on a budget had taken it's toll!  Finally I have replaced the two 6 volt batteries with 2 Motobatt MB5U batteries which fit in the existing battery boxes and each gives 12v, 7 Ah and a CCA of 90A.   Connected in parallel they have the power to easily start the engine first or second time every time what ever the temperature.   At £40 each they are a cost effective solution.   
I know Al wisely warns about uneven charging problems with this set up and recommends one big 12v battery under the seat but it is a solution that works well for me providing I use the bike regularly and check that the batteries are fully charge every 3 months or so as routine maintenance.   For example on Wednesday I carelessly parked the bike for an hour with the indicators merrily flashing away.  When I came back I assumed the batteries would be too flat to start the bike.  To my amazement it started without hesitation first press of the button!   That certainly wouldn't have happened with my old 12v Yuasa YB5LB batteries which were only 12v, 5.3 Ah and CCA of 60A each.   
I hope that helps you persevere with your Electra, with all the work you are doing you will soon have a really enjoyable, sprightly, well handling, reliable and handsome bike which starts on the button every time!    They can even be made oil tight............most of the time!   One of the great bonuses of Norton Lightweight ownership is the friendly and generous advice, encouragement and support of the club's experienced Lightweight experts on this Forum.  Good luck and keep us posted on progress.   I'm off to wash and polish mine, in anticipation of curing that frustrating oil weep thanks to Peter's sage advice!   
Best wishes
Nick

A very neat and simple solution John, most impressed.   If I had a lathe I would have machined a grove for the O ring in my filler cap the way you have.  If I'm not successful with the original fibre sealing washer from Andover Norton I will ask my local machine shop if they can machine a similar groove for an O ring.   Good luck with yours!
Nick

My experience too on my Navigator Al!   Sadly the Electra came with the weepy O ring fitted.   I'm looking forward to the correct fibre washer from Andover Norton arriving tomorrow....fingers crossed it lives up to the original spec!
Nick