I have a 1949 ES2 I have been restoring (first ever British bike I have owned) I took it for a short test run today up and down the road. My question is really about the air lever (choke) the bike ran much cleaner with the air lever fully open, is this normal ? Im used to using choke to start then close when warm, I had the advance/retard in about the middle. Any advice would be appreciated .
Also it sometimes missed 2nd gear changing up and went to 3rd but coming down was ok, any ideas ?
The choke on your Amal 276 carb works opposite to that used on more modern machines or the manual choke on a car. The reason for this is it has a slide that drops down to choke the carb, then when warm you pull the lever back to lift the choke slide. This is not the ideal method, so make sure the lever is kept tight as vibration, gravity and the spring want to try to let the slide back down.
The advance/retard lever works in the opposite way. If set correctly the bike should run under most conditions with the lever pushed forward. To start, pull the lever back about half way and you can also use this position when left at tick-over or when dawdling in traffic. An easy way to check how the ignition is set is to idle the engine on a slightly fast tick over and see if the bike runs at both ends of the lever moment, although it will sound quite flat on full retard. If it falters at either extreme, then you should think about re-timing it.
Re. the gearbox problem, if you have the upright box with the external linkage, this may be the problem as the linkage holes wear if not kept lubricated. You might get away with just fitting new clevis pins, but make sure they are 1/4" not 6mm. Before you re-fit the rod, put both the foot-change lever and the gearbox cam-plate lever in the 2nd gear position and adjust the rod to fit. In the situation of a very worn linkage, you may only be able to select 3 of the 4 gears.
P.S. Are you the same Mick Gomme I went to school with in the late 1960s ?
Thank you so much for all the information, I have only ever had modern bikes and always wanted a vintage Norton which I now have. Just getting my head around how it all works.
I have attached a photo of the gearbox, is this the type you are describing ? You will also see I have a bad oil leak which is dripping from the lower rear bracket of the chain case, Im guessing I need to start by replacing the seal and checking its not over filled ?
P.S I wasn't at secondary school until the late 70's early 80's.
" The advance/retard lever works in the opposite way. If set correctly the bike should run under most conditions with the lever pushed forward. To start, pull the lever back about half way and you can also use this position when left at tick-over or when dawdling in traffic. "
Be careful as with some years the setup is tight wire advance (what you describe is slack wire advance which is preferable as if the lever slips it goes to full advance rather than retard). I can't quite remember but I think 1949 was tight wire as the inlet cam was driven by the exhaust cam rather than direct from the crankshaft thus reversing its direction.
The only way to absolutely confirm this without removing th timing cover is to put the bike on the centre stand, take out the plug, put it in top gear and rotate the rear wheel forwards (as if in normal motion). Look at the contact breaker which is in the end of the magneto and you will see it rotate. If it rotates clockwise and the control cable enters the front of the magneto housing then it's slack wire advance. When the cable is pulled that rotates the cam in a clockwise direction thus making the points open later and retarding the ignition.
Stick with it Mick, these bikes can be quite intimidating at first but very rewarding when you master them.
Thank you Ian
A picture paints a 1,000 words! Ian was correct to raise the possibility of your magneto, as many old bikes of this age have had parts changed over the years, and your machine is no exception. The engine in your bike looks to date from 1955 or 6 and has the Welworthy alloy head. If that's the case it should have the prefix K4 (1955) or L4 (1956) on the crankcase, so all the info I gave previously will be relevant, as the magneto rotation was revised for 1948.
The gearbox is the original upright I referred to and the linkage is behind the oil pipe. Double check where the oil is coming from, it might be from the engine breather pipe, then dripping down. These old Nortons have several areas for oil leaks, so keep us posted on your old bike induction.
The school reference was a bit of a long-shot, but you never know after all those years!