Naughty Nigel

Thanks, will do. NN

It's well worth while having the cylinder honed. This breaks any glaze and the hone marks hold oil, which will help to bed in the new piston and/or rings. However, check the bore for ovality, and for a wear ridge at the top of the bore. If there is a wear ridge it might break new rings unless ridge-dodger rings are fitted. (I don't know if these are still available.) An oval bore may also allow piston slap and excessive oil consumption. In either case a rebore might be the best option. You can also break any glaze in the bore with 400 grit wet or dry paper and a bit of oil. Try to rub at 45 degrees rather than up and down the bore. Just make sure you wash it out thoroughly afterwards. NN

For future reference, you need a 'drift' with a sharp end that will just register on the slight lip behind the bearing. A peice of 1/2 inch tool steel is ideal. Gentle heat (from a hot air gun or hardryer) will help at the start, but don't get carried away with a blowtorch as that could cause distortion, and may also change the temper of the steel. Anything more than hand hot, or which burns the paint (about 160 Deg C) is too hot, The secret is to tap GENTLY but firmly on one side of the headstock, and then the other side, alternating between the two, and at points in between on one side then the other. (Think of it like a clock. Do 6 and 12, 6 and 12, then 9 and 3, 9 and 3.) If you bray it too hard the bearing will simply get wedged, and it won't go anywhere. NN

Sorry if I have missed anything on this thread, (there is a lot of it) but single wire regulators are usually just a simple Zener diode wired across (in parallel with) the battery. When the battery voltage exceeds about 13.5 volts the Zener diode starts to conduct, thereby preventing the battery from boiling dry, and brake lights from popping! These are crude but effective, and can get quite hot, so they have large metal fins, as often seen on older British bikes. There is no reason why a 12 Volt Zener regulator from (say) an old British bike should not work on any other 12 Volt machine as long as the generator output is no higher than the bike the regulator was designed for. They really are that simple. And if you cannot find one they are easy enough to make. Secondly, the misfiring problem sounds as if the ignition system doesn't have enough energy to generate a strong spark at higher speeds. (Higher engine speeds and cylinder pressures require a higher spark plug voltage.) On old contact breaker systems this was often caused by setting the gap too wide, (which meant that the 'dwell time' (or contact breaker closed time) was insufficient for a strong magnetic field to form in the ignition coil). This should not be a problem with modern CDI systems as the spark is created by a massive pulse of current (200 Amps or more) delivered from a capacitor charged to 250 volts or so. However, setting the spark gap too wide can cause similar problems. It should also be obvious that with such high currents flowing in the ignition circuit, (admittedly for a very short period of time - a few microseconds at most), all cables and connectors must be clean and in good condition if they are to work properly. HTH. NN

Thanks guys. I have been wiggling and pushing the filler cap down, but so far no luck! I will keep up with the WD40 treatment for a while to see what happens. I seem to remember that the filler cap internals were prone to condensing moisture, which will encourage corrosion. On a completely different topic, the front brake had become very spongy, which didn't surprise me. However, when I opened the master cylinder it was filled with a brown, crystalline mush, which I had to spoon out! (It looked rather like aluminium corrosion salts, but brown, although the inside of the reservoir was not corroded.) Once I got it clean I filled the reservoir with fresh fluid, bled the system through several times and it was fine. NN

Thanks guys. That is my plan. I wouldn't mind taking it over for the MGP again for some fresh Manx air and the whiff of Castrol R, but I think 'management' might have something to say about that. NN

As I posted in the New Members forum, I decided to dig my trusty YPVS out of the garage over the weekend, and have been giving her a good clean and polish. It looks as if I will need to fix the fuel tap as it leaks when I try to turn it. I gather there are seals kits available so that should be easy enough to do. However, the aircraft style fuel filler cap is more of a mystery. The key turns, but the cap will not open. I have tried removing the Allen head screws, but these don't seem to get me anywhere. And in any case, if the locking mechanism won't retract, the cap won't open regardless. I have a horrible feeling that I might have to drill it out. Is this a known problem, and more to the point, is there a known fix? I have been spraying WD40 into and around the lock in the hope that it will help free up whatever is stuck. The key turns very easily and doesn't seem to have any spring pressure, but will only go about 1/8 of a turn before it stops dead and will go no further. It is a long time since I have ridden the bike, but I seem to remember there was some spring pressure when turning the key, and that it turned about 1/4 of a turn before the cap opened, but I could be wrong. Any help or advice would be gratefully received. The bike has only covered about 8,200 miles since new, so there is not too much wear anywhere, and it is all pretty well bog standard. NN

Hi folks, After too many years of not riding I decided to dig my trusty YPVS out of the garage over the weekend, and have been giving her a good clean and polish. I had thought of selling her, as I am getting a bit old and rounded to be doing daft things on bikes, but seeing her sleek black and red lines I might just rethink that one. It looks as if I will need to fix the fuel tap as it leaks when I try to turn it. I gather there are seals kits available so that should be easy enough to do. However, the aircraft style fuel filler cap is more of a mystery. The key turns, but the cap will not open. I have tried removing the Allen head screws, but these don't seem to get me anywhere. And in any case, if the locking mechanism won't retract, the cap won't open regardless. I have a horrible feeling that I might have to drill it out. Anyhow, it looks as if I will have a few weekends of fun. Unfortunately it also looks as if I will have to ditch the tyres. They are hardly worn Pirelli's, but the rubber has obviously gone off as they are so hard. There is no point if I cannot get my toes on the tarmac through bends in the wet. Other than that I don't expect to have too many problems, but I shall no doubt be calling in from time to time to ask for advice from those who know. I look forward to your company. Naughty Nigel