problem starting when hot

[Guest]

I have a Suzuki 1983 gs1100e, the bike fires up really nice when cold and runs perfect all day long, but when you shut the bike down after riding it for at least 20minutes, the bike does not want to start back up, when I hit the starter button the starter turns over but very very slow, almost as if the bike does not have the right amount of battery power to turn the starter over... But if the bike sits for about 2minutes it will start right back up again with out any problems... I have put a volt meter on the batter when the bike is cold and it measures 12.5 and when I go to start the bike when it is cold the voltage will drop to around 11.5v... when the bike warms up the volt meter shows 12.5 too... but when I hit starter button when its warm the voltage will drop to 6.5volts and cause the starter to turn over very slowly but not the right speed to start the bike up.. Can anyone tell me what the problem might be on this. I have swapped starters with no effect, but not sure if both the starters are bad..

[eil]

Sounds to me like a bad battery, possibly with a bad charging system as well. Pretty sure voltage should not drop to 6.5v even with the engine cranking.

How old is the battery?

Run through posplayr's charging system quick test and report the results: http://www.thegsresources.com/_forum...92#post1272192

[posplayr]

I have a Suzuki 1983 gs1100e, the bike fires up really nice when cold and runs perfect all day long, but when you shut the bike down after riding it for at least 20minutes, the bike does not want to start back up, when I hit the starter button the starter turns over but very very slow, almost as if the bike does not have the right amount of battery power to turn the starter over... But if the bike sits for about 2minutes it will start right back up again with out any problems... I have put a volt meter on the batter when the bike is cold and it measures 12.5 and when I go to start the bike when it is cold the voltage will drop to around 11.5v... when the bike warms up the volt meter shows 12.5 too... but when I hit starter button when its warm the voltage will drop to 6.5volts and cause the starter to turn over very slowly but not the right speed to start the bike up.. Can anyone tell me what the problem might be on this. I have swapped starters with no effect, but not sure if both the starters are bad..

Well it sounds like either battery or starter, but I don't suspect the battery does not comes back after cooling down. It was never bad in the first place. One of the reasons that the Quick Test doesn't try to monitor battery voltage when the engine is cranking is exactly for the reasons you are encountering. How do you tell the difference between bad battery and bad starter? Not easily is the answer.

If we assume your battery is fine 12.5v quiescent and 12.0v with just key on, then there is a big load drawing down that battery to just 6.5v when you are cranking hot. Since the motor is not getting harder to crank when hot, it must be a short in the starter.

Sorry, why two starters do the same thing? Coincidence?

Double check the first two steps of Quick test to confirm the battery does not drop more than 0.5V . That means battery is more or less good. A slow crank or deep voltage drop means starter is bad.

I have never heard of a solenoid shorting the battery, but I guess that is possible. If you don't have a current meter to measure it, you could also disassemble and clean the solenoid as a desperate possible source.