Battery problem?

[Jebus23]

Just replaced my signal generators with a Dyna S. Its a 1980 GS550E. I thought this would have solved my weak spark issue and had the bike running tonight. Wrong. The volt meter on my battery reads 12V however when I hit the start button the engine struggles to turn and eventually fails and stops just as if the battery were low. Volt meter back on it....12V. My question is what could cause the bike to do this? Is my battery shot?

[almarconi]

At rest your battery should read higher that 12volts. I would expect 12.5 or slightly higher.

How old is the battery?

Make sure the water is topped off and put in on a charger, see if the voltage comes up. If not replace it.

When I am testing a bikes electrical system, I usually use a spare car battery rather than drain the bike battery. You can try to give the bike a jumpstart using your car battery(just make sure the car is turned OFF) to see if the bike will start.

[lucabond]

Weak spark can be caused by having less than full voltage at the coils due to poor connections in the wiring.
When you charge the battery do it at 2 amps or less or you can damage it. How are the connections to your battery nice and clean both pos and neg. Follow the large red wire from the battery to the solnoid make sure its nice and clean at both ends and the 1 going to the starter too. i prefer steel wool it does a better job then sand paper. Good luck

[Jebus23]

I have topped it off and charged it twice now and I get the same results. The battery is 1-2 years old but used only about 200 miles. The rest of the time it sat...and drained quite a few times.

[almarconi]

Start the bike using the car battery. If it cranks and starts then your bike battery was probably bad. You should leave your battery on a trickle charger if it is going to sit for long periods of time.

[barsnake]

Battery Problem?

You can take the spark plugs out to lessen the load on the starter. The engine should turn over faster so you can check other things, like the spark from your upgrade. The car battery is a good check. Two years is all I would expect from a lead acid bike battery. It's cheap to replace and a weak battery will ruin your charging system which is "not" cheap....

[lucabond]

Have you tried to jumping the solenoid with a screw driver ? What was the voltage of the battery after you charged it ?

[mark_vaughn]

i prefer steel wool it does a better job then sand paper. Good luck

CAUTION!
Make sure you disconnect the negative on your battery!! Steel wool gets REALLY hot REALLY fast when shorting something out...

Don't ask how I know this, just take it at my word.