Transalp not started since August. Battery flat (7.4V) Jumped it off the Pan and left it running. After about 10 minutes it ran with the jump leads off. Voltage at tickover (everything off) from about 12 to 13.2 but averaging about 12.7V. BUT when I rev it the voltage drops. I went for a ride round the block and any drain (brake light, indicator) knocked the rev counter out but it came back when I let the engine idle.
So basically there's charge enough to charge at tickover but not when there is greater demand for the spark plugs.
Battery now at 11V so still pancake-flat. My theory is the bike will behave once the battery's healthier (or replaced). Am I right, or do I have a weak alternator or RR problem (which were not there in August)?
Thanks in anticipation...