Tuesday, 21 February 2012

Meteor Minor swing arm mod

And here is the machining to allow the 50 year-old swing arm to take a two year-old spindle and stub axle. Steve Baker also ensured the axle, when fully pushed forward, is exactly parallel with the swing arm pivot. A nice touch. Q Prep Engineering Services: 01832 270027, info@qpepr.co.uk

Monday, 20 February 2012

Morini 500 Camel wiring diagram

And here, just for a laugh to see whether anyone downloads it, is a wiring diagram for Hugo Wilson's Camel. The original is in three sections, according to dotty Morini practice. This one cuts out all that superfluous nonsense and adds Benjy Straw's cunning 12V battery to ensure good lighting at low rpm. I also discovered an error in the original diagram: a spurious connection at the fuse box between the green-and-yellow and white wires. That blew a few fuses until I figured it out.

If that isn't the most obscure motorcycle wiring diagram on earth, I'd like to know what is.

Indian Enfield forks and wheels, Redditch twin frame

After a good stripdown and clean, I had a look at what was there. The answer was: not much. John's last ride on the bike, just before Christmas 1967, had ended in a low speed spill, after which he seemed to have stripped most of the road stuff off. Bearing in mind the idea is to improve the chassis, that left just three useful items: the engine, frame and fuel tank.
I eBayed almost everything else in an attempt to raise enough dosh to buy the new parts: 18in wheels, more modern forks and shocks, light aluminium mudguards, slightly more rearset footrests (Hitchcock's do a Bullet kit) and so on.
Then, amazingly, my friend Gary Inman rang asking if I could rewire his Project Enfield Street Tracker project, due on the front cover of the next issue of Sideburn magazine http://www.sideburnmag.blogspot.com/. His offer: if I built him a custom loom he'd give me everything left over from the project. I almost ripped his arm off. The haul included two 500 Bullet wheels from a 2009 EFI model, some forks, a seat, a speedo, some switchgear, and various smaller parts.
The front end bolted straight in.
The back needed a little bit of machining at the excellent Qprep of Oundle, Northamptonshire.

Wednesday, 11 January 2012

Royal Enfield Meteor Minor 500 twin

Here's the new project: it belonged to my old friend John Robinson, technical editor of Performance Bikes. I plan to restore it along the lines John would have chosen: better suspension, brakes and ground clearance, more comfortable riding position.
Early days, but it should turn out to be a handsome beast. Styling, if I can afford it, will resemble a Series 2 US export Interceptor – small tank, chrome and upswept pipes.

Monday, 9 January 2012

BSA A50/A65 wiring diagram

I've cleaned up the old wiring diagram which I first drew in 2009, and which has since been downloaded 44 times by people in India, Australia, Canada, the US and elsewhere. This new version is easier to follow. It shows a bike with a non-standard ignition switch, Boyer Bransden electronic ignition and a 12V conversion with Zener diode. Not how I'd do it now, but it worked OK.

There's a good quality hi res version free to download here:


What goes wrong with NX650's Keihin carb?

1000 miles later nothing has broken, fallen off or worn out. Considering how worried I was when I first saw the inside of the engine, that's a decent result. The one nuisance is a tendency to stall approaching junctions, even though the bike ticks over and pulls away perfectly well.
Another owner, Simon Relph, says they all do that, and the best cure is a new carb from an XR600. I've also talked to the previous three owners and they all say the pre-rebuild bike stalled like that for years. The question is, why?
Assuming the ignition and valve clearances are fine, and taking Simon's observation that a new carb fixes it, I decided that the carb must still have some problem despite professional cleaning. Replacement isn't cheap, and the carb isn't worn, so it must be possible to put whatever is wrong right. Maybe the design makes some of the small bleed drillings incredibly prone to gumming up?
I stripped the carb down and spent a long time with carb cleaner and compressed air, trying to ensure the four pilot drillings were clear. These are the holes which the pilot adjustment screw covers or uncovers as you screw it in and out. I concentrated on these bits because when I tried to set the carb up originally after the rebuild this screw made virtually no difference.
Carb reassembled and fitted, fire it up – still no good.
I have found some extremely small drills. They may come in handy.

Tuesday, 6 September 2011

NX650 restored

After a month and 500 miles of debugging the bike is pretty sorted. The rear master cylinder turned out to have a blocked return port. It was the one thing on the entire bike I didn't dismantle and clean, and the heat from the dragging pads cost me a new rear disc.

I replaced the cracked Bridgestones with new Dunlop Trailmax. Like other Dunlops they feel very stable, and glutinous as you lean over. They're good in the wet, and grippy enough in the dry for this kind of bike. If the Dommie is allowed onto Classic Bike's end of season Burn-Up at Rockingham circuit I reckon they'll be up to it.

I'd originally put Putoline 10W oil in the forks, which was too harsh. Honda recommend ATF which turns out to be quite light – equivalent to something like 2.5W Putoline. Since changing to that oil the front end is comfortable, though I've forgotten how crude these old damper rod forks were.

There are two problems left: first, the rear caliper bolts and bushes are worn, giving lots of lost motion at the pedal and a vague rear brake. I might need a new caliper, though it easily passes an MOT.

Second, the engine stalls round town and doesn't respond to Honda's recommended pilot screw adjustments. It could be that some fresh dirt got in there after the clean-up, so I'll check the pilot galleries. Otherwise the motor feels like new. Valve clearances are stable and I've revved it to 6000rpm without trouble now.

It's great to have breathed new life into a bike that belonged in a skip, and Fiona loves buzzing around the local lanes on it too.