OK, I have a 1982 Yamaha Heritage Special 650 CC motorcycle. It will not keep a charge. The guy I took it to said he could find nothing wrong. I can drive it about 70 miles and then my husband has to get me with a trailer. The battery will recharge and I can go another 70 miles +/-. Any suggestions?
I don’t know jack about motorcycles, but on a car I’d say this was caused by a short in wiring somewhere. There may be wires somewhere that have rubbed against something and are grounding out. Since there aren’t many places to look here, start around the ignition area.
Since you lose battery during a drive, the obvious culprit is the charging system. Have your alternator/generator checked out. Examine for loose or corroded electrical connections.
Put a volt meter on that battery after it is charged. It should read a little over 6V or 12V depending on the battery. Now start the engine and get it a little above idle. Now check the voltage again. it should be about 10% higher. If it is lower or the same, then you have a charging system problem.
I will try that . Thank you so much!!
How old is your battery? Unless they are trickle charged on a regular basis, they don’t last long in my experience. If the alternator is working properly and the battery is old, then invest in a new battery and a “Battery Tender” charger.
The original battery in my 1999 Shadow lasted less than a year before it failed since I didn’t maintain a charge during the bike’s first winter. I started using a Battery Tender with the second battery and it was going strong after 2 1/2 years later when I sold the bike. I’ve found the charging system on older bikes (I had an 82 Honda Sabre) was good enough to maintain a charge on a good battery, but not strong enough to charge a weak or discharged battery.
This is almost certainly a bad rectifier/regulator. Japanese motorcycles of that vintage usually have an integrated rectifier/regulator unit that can go bad. It then fails to charge the battery. I had to replace one on a Yamaha in the late '80s. Basically, you are running off your battery until it can no longer fire the ignition system. I rode my bike to work for a week or so by recharging it each evening until the part arrived. Should be an easy swapout.