ANY HELP, ROUGH START!!! 05 GS500F

[chdaly]

     Two years ago I bought this 05 GS500F from my brother for $800, claiming that it ran. Come to find out the exhaust valve shims were closed (thanks to this site). I proceeded to basic tune the bike. Oil, filter, spark plugs, battery, and even ran through the carbs. Setting A/F all the way in and back out 3 turns. Bench synchronizing the butterflies. Even adjusting float height were one side is dead and and other side is a bit low but not drastic (thanks gstwins.com). 

     After all was said and done i choked the carb, turned it over and would not start. Brand new 93 octane, hmmm. My friend had the great idea to spray starting fluid and that fired it right up!!! WOOOHOOO!! 

     The problem is the bike will fire up on choke and rev out but like burns out the fuel and dies out. After burning out it will not start on choke, half choke, or run without the help from starting fluid. Once the engine has warmed up from the help of starting fluid and revving it will idle and run pretty well. Just dont understand what it needs to fire up on its own?!?! 

[qcbaker]

Sounds to me like a fuel delivery problem. It runs on starting fluid, so you have air, spark, and compression. Only thing missing is fuel. Have you verified that the choke is actually working properly? A broken or frayed choke cable could cause the problems you describe.

[Watcher]

Could be a possible petcock issue as well.  See if it works on the PRI setting.

[qcbaker]

Could be a possible petcock issue as well.  See if it works on the PRI setting.

I thought that as well, but I couldn't figure out why the bike would run/idle normally after being warmed up on starting fluid if the petcock were the problem.

[Watcher]

Could be a possible petcock issue as well.  See if it works on the PRI setting.

I thought that as well, but I couldn't figure out why the bike would run/idle normally after being warmed up on starting fluid if the petcock were the problem.

Not creating enough vacuum at idle speed, fuel only flows when revved up?

It's always a good troubleshooting step either way.