I am trying to get an older 1993 GS500 running and I've had just a little success so far.  At the moment the bike will start up after having sat for a day, it will run for 2-3 minutes peaking at as high as 8000RPM, than it will slowly die down until it stalls out.  After that it is very difficult or seemingly impossible to start.  The plugs get wet, almost making it seem as if there is a problem with the ignition.  I've bypassed the gastank completely, got new needles and seats for the carbs, new plugs and they are getting spark, not sure what to do next.

Pull your air filter an spray some starting fluid in the air box when it starts to die if it perks up than it's a fuel issue, if it's dies check your  coils.

I when I synced my carbs I had a Issue with that after I put it all back together. Turns out I forgot to connect one vac line.


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I have sprayed some starting fluid in the air box with the filer in and it made no difference, didnt try it with the filter off I dont think.  What more can I do now though, buy new coils?

It could be coils.
It could be timing pickups.
It could be the ICU.

Heat can make any of them fail then work OK again when cold.
You can spray something cold on the ICU when it fails. You can remove the timing cover and spray cold on the pickups.
A can of air upside down is a good freeze spray. Many spray cleaners (carb or brake cleaner) are also cold.

.... Never ever Spray stating fluid on the air filter, if the carb back fires you  filter will burn


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....lessons learned the hard way, you'll never forget


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