The multi meter's showing no charge going into the battery at all, so time to rebuild or replace the alternator. We took it off late this afternoon, but then realised we need it as the fan belt also powers the water pump, so without it we can't run the engine.
I'm happy to admit I'm no mechanic. I know what goes on inside an engine, but I'm rubbish at fault diagnosis & cure. So I'm finding myself standing by, watching Terry & Kev & awaiting instructions to start the engine, rev the engine, stop the engine etc, as required.
Between them, they've managed to get the motor starting reliably & ticking over. We, (they), had a problem with the engine overheating. The water system was becoming highly pressurised & we could hear popping from the mouth of the carb, followed by hissing from the inlet/water distribution manifold when we switched off. Turned out, as terry said, that the cooling fan wasn't cutting in &, with the radiator a couple of inches below full, the water in the system was turning to steam. Eventually it blew out of the expansion tank overflow pipe, as it's designed to do, in spectacular fashion. The pops we could hear were fuel detonating as it hit the bottom of the hot inlet manifold.
The fan fuse had blown -I think the pre-wired fuseboard was fitted with a 10amp fuse when it needed a 20. Terry replaced the fuse & put a bridging wire across the fan switch terminals so that it runs all the time when the ignition's on. After Kev had left for home, Terry & I refilled the radiator & ran the engine for 20 minutes or so with no problems at all. Over the next few days, I'll run it again & if all's well, will remove the bridging wire & see if the thermostatic switch cuts the fan back in when it gets up to temperature.
The tick-over hunts a bit -it rises a falls in a rythmic fashion & the fuel pump ticks in a similar way. Not humming, but ticking quite loudly as it does when the pump's dry -any ideas?
Having removed the baffles from the ends of the exhausts so that the SVA testers can push their emmissions testing probe into them, it's now reading 106 decibels. So I think I'll have to replace the baffles & extend the tail pipes a little.
Kev needs his vacuum gauge to fine tune the carb, but according to his gas analyser, the emmissions are reasonable.
Once the engine's hot, the hydraulic tappets get very noisy. First course of action is to change the oil & filter -it's still using the same lubricant that was in it when I bought it about 3 years ago.
So I need to buy or borrow a Rover SD1 alternator & change the oil. That's my instructions for now.
As always, many, many thanks to Kev & Terry. Really appreciate your continuing help guys.