Many thanks to those who have taken the time to send in their entries for the competition I ran in last month’s magazine. I will announce the winner in the June edition so you still have time to do some more research and send in your entry. I am very pleased to report that interest in the older, historic karts appears to be at an all time high. I have had many calls from drivers who raced in the early sixties, all expressing interest in the historic karting movement and requesting membership applications to the Spirit Of The Sixties Kart Club. One reader who got in touch was Alan Button who went to the World Championships in 1960, held during Nassau Speed Week in the Bahamas, along with with the likes of John Brise and Stirling Moss.
People like Alan will bring a wealth of much needed information to the events and reunions planned for 2006. On the restoration front, I am pleased to report that the 1962/3 Paul Fletcher Bitsatube/Montesa M100 will soon be finished and back on the track. It’s just over 40 years since its last outing and I can’t wait to see how it performs. Paul and his father built this ultra lightweight kart for the first round of the European Championships, held at Bergamo, Italy on the 7th April 1963. Many thanks to Paul Fletcher, Dave Bewley, Mark Burgess and John Mills for providing invaluable information during the restoration of this very special machine. If anyone out there has any photographs of Paul on this kart, or other relevant information, I would very much like to hear from you. If you are currently restoring an interesting historic kart or engine and require help or information, why not ring the helpline number. I will do my best to answer your questions and give your project a mention in Ancient & Modern.
It would be good to see a few more 1960s Class 1 karts during the 50th anniversary celebrations. Keep looking, the karts are out there! 100cc Engine Restoration (Part 3) Having covered removal of the top end of the engine last month, we can now move on to the crankcase and generally inspect the bottom end. Remove the drive sprocket and its key and the ignition rotor and its key from their respective crankshaft tapers using the tools discussed in the last article. Have a good look at the crankshaft tapers and their keyway pockets. The tapers should be in good, smooth condition with no scoring and the keyway pockets should be in good crisp condition. It’s worth checking the output shafts for bends at this stage using a dial gauge and a stand at various points along the shafts. Any problems with any of the above will probably require a replacement crank assembly. Have a cup of coffee (or something stronger), before reaching for the helpline number. Assuming all is well so far, remove the ignition statorplate, usually held in place with three short screws and washers. If you have CEV flywheel ignition it’s a good idea to mark a point on the statorplate that corresponds with a mark on the crankcase. This will help you to reset the ignition timing when you come to reassemble the engine. Disconnect and remove any ignition coil that may be fitted to the engine and make a note of how the wiring is connected. Now you can remove the nuts or screws that hold the rotary valve cover in place.
Carefully pull the cover off, trying not to break the thin circular gasket. With a marker pen, make a mark on the outside face of the rotary valve, this will prove helpful when reassembling the engine and for checking the inlet opening period. Next remove the rotary valve driver and its locating key. Again, check the crankshaft and keyway pocket for damage. Now you can remove all the bolts joining the crankcase halves together and separate the crankcases. Try not to damage any gasket that may be between the halves. Only use a soft aluminium wedge if you need to prise the halves apart and don’t forget that there are usually locating dowels in one half which can be a tight fit into their corresponding holes. Carefully remove the complete crankshaft. The main bearings will usually be captive in the crankcase halves and should be left alone until we discuss removing them from their housings in a later article. Under no circumstances be tempted to drift them out of their housings with a hammer and punch! That’s it for this article, next time we will examine the parts removed from the engine and decide which parts need to be replaced.