Why do you want to fit a 'Kubota' alternator? Kubota do not make the alternators which they fit to their engines but use Nippon Denso units. Two models are typically used on Vincents. One is a small unit, about the size of the palm of your hand, and is a permanent magnet type, The other is about 3.5" diameter and about 5" long. That is a more sophisticated unit containing exciter coils etc. The latter will give 40 amps! The former more like 12-15 amps. Dick Sherwin and I developed a kit to fit alternators intended for use on small Citroen cars, eg 2CVs, Dyanes, Amis etc to all post war models of Vincents and there are now about 40 of these kits in use. The alternators produce 30 amps. These kits are made on a non commercial basis and you might have seen them in use at various Vincent rallys. I cannot use this forum for what might seem to be commercial purposes but if you email me on
enw07@btinternet.com then I can send you photographs of the kit fitted to various bikes, twins and/or singles, and send you a copy of the fitting instructions to show you what is involved in fitting the bits. No part of the bike has to be modified to fit our kit so it does not affect the long term value of the bike. Ask about if you wish about the long term reliability of our units. So far no one has had a problem and some people are so pleased that they have bought more than one to fit to their other Vincents.