Hey guys new rider here just encountered a new problem or at least something that hasn't happened before. I used to be able to start my baby up just fine and i'd put the choke on like 75 percent for a few minutes and then be on my way. but the thing is, i COULD start the bike just fine without choke really and ride off just fine.Now, I can't start the bike without choke, and even after like 10 fuckin minutes the bike will still die unless i have the choke partially on. I used to ride completely with no choke. Is it bad to ride with a the choke lever down a little bit? Why does my bike need the choke now? it's annoying. Yeah so probably a real obvious answer to this question, but i'll never learn more unless I ask. Thanks for the help.

When's the last time you checked valves? Tight exhaust valves will do this I found out...

Used to start well but now it gets more and more difficult = tight valves. Usually.

Have you checked them?

Michael

Poss` just running lean on mixture srews?

start simple, forget about valves and other complicated stuff and make sure your idle isn't set too low (screw between carbs accessible without taking off anything)

good luck

EDIT: I know that you said bike used to run good, but GS500 engine vibrates quite a bit so theoretically the screw might have unscrewed itself 

How old is the bike?  Possible vacuum leak, but first try the idle screw, like KML says.

Mine does the same sometimes. Every time I start it up, I need to run it about 5-10 minutes on half or full choke to warm up the bike (usually 5K RPM with full choke on is good)
I've dismissed this as normal, but I'm thinking something else now. Any input?

dam! you let the engine idle at 5000rpm to warm up?!? after 2 min ill bet the headers are glowing. why not use just enough choke for it to idle at 1600-1800? hell you can even ride it like that.