Mk 3 - Electric start/ failing battery.

I have a Mk 3 with a Yuasa YTX16-BS 12 volt 14Ah battery. The battery is about 5 - 6 years old and sees a fair bit of work in the summer but very little in the winter, when it is usually on the Optimate.

900 miles into an Irish tour ( very much back roads and country lane work) the starter mechanism has failed in the sense that all that happens when I press the starter button is that the starter motor whirrs away but nothing otherwise engages.

Having said the above, when I initially arrived in Ireland I noticed that when I used the starter it sometimes would not turn the engine (usually first press of the button) but on subsequent attempts it would turn the engine just a few revolutions and then give up. It did however always start ( usually 3rd or 4th attempt). Nb the trip to Liverpool to take the ferry to Ireland was a fast motorway journey so the battery should have been well charged.

I’ve taken the battery off the bike and the voltage between the terminals is 12.79 volts.

Electric starts are not really my forte so my questions are:

1. Does the above indicate that notwithstanding the voltage reading, the battery needs replacing ?

2. Does the failure of the starter mechanism to engage relate to voltage issues or is it likely to be something completely different ? Also, is there a quick fix or is it likely to be a primary side strip down ?

PS The bike has not been ridden with the headlights on and the ignition light has not been staying on once started.

PPS The good news is that the bike invariably starts first or second kick on the kickstart !

Thanks, Alan.