Still not sorted.
Motobatt battery arrived today. 1st prod and the bike started
. Switch off, try again and its very sluggish and a non-starter.
Motobatt still showing 12.7 volts, so now convinced its the starter and as I have stripped, cleaned and reassembled about 4 times its clearly broken beyond my capabilities now. Two eBay sellers do the Arrowhead starter but neither have any actually in stock. So started ringing around including a local autoelectrical firm who are very helpful and say what I have got could be refurb'd but cant say how much or how long it would take until they get into it and understand the components and if its not standard stuff from the car world it could be 1-2 weeks while they source the parts. But they could get me a pattern part which turned out to be an Arrowhead for a little bit more than the eBay sellers, and it would be delivered next day. So, hopefully that will turn up bright and early and I get it fitted and relax again.
On the Motobatt, after hearing only good things about them I am more than a little disappointed initially. I ordered the model recommended on the Motobatt website (MBTX9U), but compared to the Yuasa I took off its physically smaller so a bad fit in the battery box which makes getting the cables on difficult, especially as I am fitting extra HD cables to wire the starter direct to the battery. And, although it has two pairs of terminals it only comes with 1 pair of posts which kinda defeats the point of the extra terminals. I spent ages rooting around my box of old/spare bolts looking for something that would fit in the extra two terminals so I could wire in my auxiliary power stuff. Done now anyway and fortunately the bikes battery strap has some flexibility so it still holds it down. Finally, the spec of the battery seems to be down the Yuasa equivalent: the Motobatt is 10.5Ah and 160CCA. The Yuasa was a YTZ14S was 11.5Ah and 200CCA. I understand the Motobatt has some different tech going on and I understand somehow or other gives more "oomph" but I will forever have my doubts.