Hey all,
ON Friday when I went to ride home I found the battery flat, tried to clutch start it a few times  without any luck and then got a jump from a car. The bike started and ran no worries until the leads were taken off and then it would idle alright but when given a bit of throttle it would blow black smoke and backfire really loudly and was unrideable. I took out the old battery and went and got a new one and everything is sweet. The old battery was looking pretty poor with many of the cells less than half full.

Do GS's need current to run? Have they got some computer thingy that controls fuel flow? Has anyoine ever heard of this before?

Its going into the shop this week and I think I'll get them to check the charging system.

cheers

Your plugs probably fouled from starting attempts ,try to clean the plugs points with fine sand paper or wire brush

bikes don't like to run with a flat battery after jumping.  I think. this happened to my honda.

my bike has this same problem.  if the battery isn't charged, it will only idle.  it's like the charging system can't run the bike by itself

thanks guys. Its good to know that other bikes behave the same way. I'll check the plugs but its now running reeeeeaaaaallly fine.

the charging system can run the bike, but very poorly. Our member annguyen ran a study, his '04F ran, but shittily. The tach (electrical on '04+) didn't operate well, bike didn't idle well, etc..

Totaly normal behaviour for a bike with a fully discharged or open circuit battery and CDI ignition. The regulator/rectifier detects the fact the battery is discharged and diverts the maximum amount of voltage/current it can from the alternator into the battery in an attempt to charge it. This causes a reduction in voltage going into the bikes electrical system and the voltage sensitive electronic based components such as the CDI module and the tacho begin to operate eratticaly due to the now reduced voltage.