| Andy,
I don't know about the Optimate, I've never had one, but regarding the charging on the bike, connect a voltmeter across the battery on the bike and set it to DC Volts. Just off charge it should show just over 13V this will drop to the high 12s after an hour or two. On switching on the ignition it will drop but should be by no more than a half a volt or so, any more and your battery is dodgy. When the engine is started you should see about 13V - 13.5 V at tickover rising to about 14V - 14.5V at 3000rpm + . If you don't get these figures the alternator or regulator is faulty. Unplug the 2 yellow leads from the alternator and connect the voltmeter across them set for AC Volts. You should read about 15V/1000 rpm. ie about 45V at 3,000rpm and 75V at 5,000rpm. If that is OK then the fault most likely lies with the regulator (and generally does).
I think it is unlikely that you've got two duff new batteries but sluggish starting implies that the battery voltage is down. However it's also worth checking the connections to the starter, particularly where the cable from the solenoid connects to the starter. It can collect water and muck under the rubber boot which causes corrosion at the terminal which reduces the current available for starting.
Hope this helps.  |