April showers

What's on the agenda today? My first wet run, on the infamous Kenda Manlung nylons. But first: some unnecessary maintenance!

I changed the oil at 0km just to get the stock unknown out. However, I couldn't get the oil filter out, so now at the heady 100km mark, I decided to do another change to get any initial swarf out. I'm still on Halford's 10W40 semi synthetic motorcycle oil, which should be more than good enough for this 35 year old engine.

After a run to get the engine hot, I drained the oil and set about the filter plug with my new multi-sided 23mm socket, which was all that B&Q had available. It rubbed almost immediately! Rotational impact, heat, rustola, nothing shifted the plug. It just rubbed and rubbed, even when I bashed a 22mm spanner onto it. The Chinese Bike Forum provided the helpful info that this plug is aluminium, not steel. Aaargh!

In the end, brute force and ignorance won out. After another liberal dose of penetrating oil, running a butane torch around the join again, smacking the bejeesus out of firmly tapping the plug around the rim, towards the engine, hammering the 22m spanner firmly back on again and then delivering a mighty whack to the end of it, the plug finally gave up the struggle and shifted.

Lesson learned: if you get a bike with this engine, find yourself a hexagonal 23mm socket. Don't waste your time - and your plug corners - with a multi-sided socket. It'll just end in tears... and barked knuckles, burned fingers...

The filter was mostly clear, although it had a few tiny scraps of what looked like plastic wrap in it. Other owners have reported this as well, although I can't think what it is or how it got in there. Ah well, it's out now, and the filter plug replaced with some copper grease and a sane amount of torque.

Next, valve clearances. Following the great instructions at that link, I got the valves exposed in no time. The CG125 owners' site agrees that the clearances for both valves should be 0.08mm (0.003 inches). Unfortunately, my cheapo feeler gauges only go down to 0.1mm, so I adjusted (loosely) to that. Skipping ahead to the ride, it was clearly too much: the valves were audibly buzzy. So I re-did them by hand, adjusting them to the 0.1mm feeler, then giving them another small turn and checking that the feeler wouldn't quite go in (but that there was still a gap!). Even with this tiny difference, the valves were much quieter. In fact, they were probably set just fine to begin with by the factory. Ah well, now I know they're definitely OK. Approximately definitely.

Since the rain was tipping down, I decided that it was time to have the side stand switch out. Rather than cutting it out and splicing the wires, I just unbolted the switch, cut the cable tie under the bike holding the cabling and plug in place, pulled the cabling up and fed it through under the seat. The whole assembly, switch and all, now lives in there, still greased up. I even cable tied tightly around the switch shaft so that it couldn't somehow become depressed. That should be that, hopefully. Now when the bike strands me in the middle of nowhere, it should be for some other reason.

One last thing before the ride: I couldn't resist the urge to fiddle with the air filter. The air box is under the left hand side panel. There's an inner 40mm-ish inlet letting in to a larger cylinder with a thick foam filter around it. Air is then drawn forwards from the space around this foam filter into the carb.

First things first, take all the filters out. Wow. Blat-blat-blat, goes the bike, very "classic". But we can't run like that, so I put the big cylinder with the foam filter back in, but left out the 40mm centre inlet. As far as I can see, all the air still has to go through the foam filter, but there's a little bit more growl under throttle. Utterly pointless, but then, so is the bike.

I'll leave it like that for now, but I've got a 43mm K&N filter on order which I can either attach straight onto the carb (removing the air-box) or perhaps even place over the box-inlet, removing the foam cylinder. I'll try to get some pictures of all this in order for it to make half an ounce of sense.

Finally, we're ready for the road. In a steady but not torrential rain, I set off. The back wheel definitely did twitch slightly while pulling away from a sharp bend heading downhill, but for the rest of the ride I was super-cautious and it behaved itself just fine. Still, it did twitch, so better tyres are on the list of things to get sooner rather than later.

Oh look, the sun's out now. And I forgot to get onions when I went out for my wet run, so... that's as much excuse as I need!