The last week or so my GS has been starting hard. It ran rich and on one cylinder but not the same one every time when it started but after it warmed up it ran okay.
Now it won't run at all.
I cleaned the carbs but the problem remains.
I was checking the spark and it seems that the spark gets better when  let off the starter button than when I'm trying to start it.
I changed the plugs, no better.
I checked the wires, they seem fine.
The battery is fully charged.
I even set the timing back to the original setting

I'm at a loss, please help  :dunno:

may be a weak battery. I know you said you checked it and it is fully charged, but it may have a bad cell.

I have a similar problem.

My GS stopped running on both cylinders in June. I changed the plugs and charged & filled the battery, and voila - problem solved.

Or so I thought...

Last week I was on the highway and the damned thing dropped a cylinder again. This time I tried changing the plugs and it didn't get better. I have ordered some new wires and hope that helps. The battery is only a year old and has always been on a tender when not being used.

:dunno:  wtf?

Any suggestions? It ran fine for over 1k miles after the first attempt back in June. Not sure what else I should do.

Quote from: ghettoriggedLast week I was on the highway and the damned thing dropped a cylinder again. This time I tried changing the plugs and it didn't get better.
[...]
Any suggestions?

If you can use an ohmmeter, here are two test procedures to try:

Check your ignition coils

Check your signal generator circuits[/list:u]Use the first photo in the first post to locate the connectors mentioned in the second post.  The 3-wire connector is the left-most one in that photo.  The 4-wire connector is the black one in the middle of the photo - tucked behind the "black box".

Update, got the bike running. Went back through the carbs and did the checks Kerry posted.
The 4 plug connecter was corroded inside. Also one of the BRAND NEW NGK plugs was bad  :x .
I also ordered new wires just to be sure.
Thanks for the help.

Ha ha NGK plug bad ... ha ha ... someone was saying they were great ...    ...
In any case - dropping 1 cyl ... try the auxillary ground ... bad connection there ... Unless you also have bad sparkies ...  :x
Cool.
Srinath.

Quote from: MXF7290Update, got the bike running.

Cool!

Quote from: MXF7290[...] did the checks Kerry posted.
The 4 plug connecter was corroded inside.

Same here!  Mine was so bad (from using a STOOPID battery-cleaning technique ) that I was not able to pull it apart:




I eventually cut the whole connector out of the circuit and replaced it with 4 individual connectors (the pink thingies):



I'm glad yours was a little easier to work with.