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Bike Profile - Posted 20th July 2012

1977 BMW R80/7 - Part 14 - A Day in the Life
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A routine service for an Airhead Boxer BMW. What could possibly go wrong? Martin Gelder tells us how it started badly and then went downhill from there...

There have been just four rain-free days in Cambridge since the start of June. I think I was at work on all four of those. There's a Big Trip looming for Roxanne the R80/R100, and I'd hoped to get her serviced well in advance of departure. You never know what horrors a bit of routine fettling might uncover on an old bike, and with any parts needing to come by mail order having a bit of time in hand can make all the difference. Because the shed is full of knackered old basket cases classic bikes working comfortably means working outside on the patio, and that's not normally a problem in summer. It has been this year.

So with less than a week to go before departure, yesterday saw me dodging the showers to get the tappets adjusted (easy on a boxer and only one out of four needed adjusting) and a new set of points fitted and timed (fiddly on a boxer because the front wheel is where you want your head to be).

Archive photo, taken on a sunny day last year... BMW R80/7 tappets, in the breeze

I usually set the timing statically using the Radio 5 method. Tune the (non-DAB) shed radio to the popular talk based service, and then nudge the dial slightly so that you're listening to static instead of Simon Mayo. Some may find this an improvement. With the ignition on, turning the engine over by hand will produce an easily audible click on the radio as the points open. No messing round with bulbs and crocodile clips or watching a meter with one eye and a timing mark with the other.

Sparks not shown. BMW R80/7 points live behind the advance-retard wotsit. Easiest access is through the front wheel.
Big Trip BMWs on now

I'd just got everything buttoned up when rain began to fall, so it was on with the waterproofs before riding up to the shops for some gearbox and fork oil. I'd gone maybe fifty yards before the bike started stuttering. Switching to reserve didn't help; the bike would tick over perfectly but cough and splutter if given any throttle. Back at home I checked fuel was getting through to the carbs and that the floatbowls weren't full of water before pointing the finger at the timing I'd just set so carefully.

There was a juicy spark at the plugs, so with rain trickling down the back of my neck I took off the timing cover to see if there was any obvious problem. The bike started on the button and settled into its usual slow lumpy tickover, but as soon as I revved it I could see sparks jumping from the auto-advance bobweights.... That's not meant to happen. A bit of probing and poking showed that the tab of the points' low tension lead connector was sitting slightly proud and allowing the bobweights to contact it and short out the ignition. Fine at tickover, misfiring as the engine picked up speed and the bobweights moved outwards. Who'd have thought? With the tab bent in slightly, normal service was resumed and I set off once again for supplies of oil, somewhat damper than before but happy that a problem had been solved.

I'll leave out the episode in the bike shop where the ever helpful proprietor tried to sell me twice as much as I needed of the fork oil he had in stock, rather than just enough of the fork oil I wanted but that he didn't have in stock. If you've seen Monty Python's Cheese Shop Sketch you'll get the general idea. The BMW, meanwhile, was running particularly well after its earlier hiccough and I decided it needed a bit of a run out to warm through properly before changing the oil. Pride, fall, etc.

The A14 passes to the north of Cambridge, carrying freight traffic, holiday makers and commuters from East Anglia towards the rest of Britain's motorway network. It's regularly grid-locked, particularly at three o'clock on a wet weekday afternoon. Did I mention that it had started raining again? Inevitably, it was while accelerating down the slip road onto the A14 that the BMW decided to die. Completely and suddenly. One minute fine, then burrrrrrrrrrrrrrrrrr..... nothing. And despite being a busy trunk road, the A14 has no hard shoulder, just a muddy ditch and some prickly bushes.

Not the ideal place to remove the timing cover, but needs must. Keeping a wary eye out for errant HGVs and preoccupied school-runners, I inspected the points and their connections. Nothing obviously wrong. I pressed the starter and the bike fired up, revved, ticked over... Harumph. More rain trickled down the back of my neck. I refitted the timing cover, got back on the bike, pressed the starter and ... nothing.

Aha! This is good. I've had this before, on a Honda 125. Removing the cover once more, I spotted the problem straight away. In my haste to refit the cover after fixing the first misfire, I'd nipped the points lead between the timing cover and the crankcases. Not enough to break it, but enough to cause a short, killing the ignition. A bit of insulation tape, a bit of careful reassembly, a bit more water down the back of my neck, a few more near misses from passing caravan owners hogging the edge of the slip road and I was on my way. Again.

[There will now be a short intermission while the rain stops and our intrepid author changes the oil in the crankcases, changes the oil in the gearbox, changes the oil in the shaft and changes oil in the bevel box. He will then go online and order a new set of points, to be delivered in 24 hours.]

Ah, the great British summer...

Right. Where were we? Tappets done, points done (done for, perhaps), various engine oils changed, just the fork oil to sort out. And with the rain still holding off, time to ride over to the other bike shop to see if they have the right fork oil in stock.

They do! I buy some, and we chat about passports and foreign rides in the sun and the need to carry spare inner-tubes (I buy one of those as well, just because they had the right fork oil in stock). All is well with the world once more as I head for home.

Heading for home from the bike shop that stocks the right fork oil involves turning right onto another busy trunk route, by now packed with tired commuters. I spot a gap, go for it...

And find myself standing in the middle of the A10 as the BMW pirouettes slowly around me, chugging contentedly to itself as it lies on its side.

A nice man in a pickup truck stops to give me time to pick the bike up and cross back to the side of the road. "What happened there?" he asks, "How did you fall off?" I can smell the diesel fuel coating the junction that the bike shop shares with a petrol station, but I'm tempted to tell him the whole sorry tale, starting with me trying to set the tappets and change the points in between rain showers...

Words and pictures: Martin Gelder

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No damage done to the bike; tough old birds, boxer BMWs. And any minute now the postman is going to arrive with my new set of points. Just got to fit them, and what could possibly go wrong with that?

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