This may be an old wives’ tale but doesn’t hurt to mention it. Guy with Triumph twin fitted with Morgo rotary oil pump knocked his bike over onto its side accidentally. Picked it up and after riding a short distance the motor seized solid. Seems that while the bike was on its side an air lock had developed around the oil pump.
Ideally he should have loosened an oil line hose clip to bleed any air from the feed line but at the very least he should have removed the oil tank cap, after starting the bike, and ran it for a while to check for good oil return. This is something you MUST do after every engine rebuild or oil change. In fact some Norton owners’ handbooks recommended when starting the bike from cold you should put your finger over the return hole in the top of the tank in order to force more oil to the rockers. This of course before Matchless engineers redesigned the rocker oiling system for them and moved the feed to the back of the timing cover.
Comes up all the time – customer complaints (some even get nasty) saying that long type Norton Commando (06-5743) and 1971 on Triumphs (97-1510) are way to small at the lower end to fit over the sliders.
These are made in Italy, as original, and they will stretch and fit – do it somewhere warm and use a little tire soap.
Piston ring sizes – I rarely work on bikes these days, the parts business keeps me hopping. However I have a couple of times recently told customers wanting piston rings to take the next size up if the size they want is out of stock. Had a guy today needing +30 for his Commando so I told him to use +40’s and carefully file the end down to get the optimum gap (4 thou per inch of bore). Wouldn’t do it “because the tension would be wrong”. Well I did it many times in the 60’s and 70’s and never had a problem – I actually preferred it with a slightly worn motor.
The spoke bend angle keeps raising its ugly head. I’ll say it again, if adjusting the bends of our spoke sets by 5 to 10 degrees when you fit them is not your thing, please buy your spokes somewhere else, and in the words of our UK manufacturer “you should not be trying to build a wheel”. Of course if you send me specimen spokes to copy I’ll get them made exactly for you, but they will be slightly more expensive.
OK it’s not quite stock – some of you will have noticed that the Amals have been replaced by a single Mikuni
Customer with 1965 650 Twin thinks his motor is not original because his frame is stamped A50****
BSA didn’t start matching engine and frame numbers until part way through the 1966 model year. All 500 & 650 A50 & A65 variants up to that time had frame numbers starting with A50.
Roy Bacon’s BSA Twin and his other restoration series books have excellent information charts in them covering engine and frame numbers.
I am quite often asked how to remove the tumbler and key assembly (Lucas no 54335169) fitted to the common Lucas 2 and 4 position switches used on most bikes from the 1960’s onwards.
In the body of the switch you will see a small hole. Turn the key to the on position, which lines up with this hole, and you will see a small spring loaded brass pin in the end of the tumbler. Carefully push a thin steel rod (the back of a drill bit works) into the hole, depress the pin and the tumbler assembly can be withdrawn from the switch body.
What if the key has been lost? You will have to very carefully drill a hole in the body to line up with the position of the key, and gain access to the pin. Grease on the drill bit will reduce the chance of little metal shavings getting into the switch.
In regard to these switches, I can’t recall anyone ever having a problem with the 2 position types, unlike the 4 position ones (fitted to 71-2 Triumph & BSA Twins and 71 onwards Commando’s). With the 4 position switches, that’s the first place to look if you are experiencing any kind of intermittent electrical faults.