Bike Won't Stau Running When Engine is Cold

[mrdrprof]

So I recently bought an '04 GS500F (my first bike), and it does not like cold starts. At all. I have to rev it up when I start it or else it will just die instantly. I leave the choke on for about 30 seconds to a minute to warm it up a little, but when I turn the choke off, it sits at about 1k rpms and then the rpms slowly start to drop till the bike stalls out. Sometimes the choke will barely work, only bringing the rpms up to about 2-2,500 rpms and will still slowly drop even with the choke on full. Once I ride the bike for a few minutes to get it to operating temp it seems to run okay. I feel like there is a problem though because my brother also owns a GS500F and his starts up and runs fine when cold.

I haven't taken anything apart yet, so what things should I look at first? I'm not really sure where to start and I don't really have any experience with carbed engines, let alone bike engines.

[Watcher]

The first thing I would do is make sure it's idling at the proper RPM when warm, as if this is set wrong it'll muck up everything else.

The second would be to make sure the choke is actually working.  You might be moving the control but if the cable is out of adjustment or the choke on the carb is stuck it won't be changing much.


FYI, leaving the choke on for about 30 seconds is hardly sufficient to bring the bike up to operating temperature.  30 seconds to a minute is about how long it should take for the bike to be rideable, and in this state you should be somewhere around half-choke.  After another couple minutes of riding it like this and the choke should be able to go all the way off.

[mrdrprof]

Thanks for the help man. Like I said, this is my first bike so I'm still learning everything about it. I messed with the idle screw and I have it set to about 1,200-1,300 rpm. Is that where it's supposed to be?

[Watcher]

Yes.  Factory spec is 1200-1400 so you're good to go there.

[Jim Moore]

These things take a LONG time to warm up. Start it, let it run while you pull your gloves on, then ride it with the choke on for a good five minutes. You can start easing the choke off after a minute or two, but it probably won't idle with no choke until five minutes or so.

[The Buddha]

So I recently bought an '04 GS500F (my first bike), and it does not like cold starts. At all. I have to rev it up when I start it or else it will just die instantly. I leave the choke on for about 30 seconds to a minute to warm it up a little, but when I turn the choke off, it sits at about 1k rpms and then the rpms slowly start to drop till the bike stalls out. Sometimes the choke will barely work, only bringing the rpms up to about 2-2,500 rpms and will still slowly drop even with the choke on full. Once I ride the bike for a few minutes to get it to operating temp it seems to run okay. I feel like there is a problem though because my brother also owns a GS500F and his starts up and runs fine when cold.

I haven't taken anything apart yet, so what things should I look at first? I'm not really sure where to start and I don't really have any experience with carbed engines, let alone bike engines.

The answers you got are all accurate - but you could also have a tight valve. Check and adjust them to spec.
Cool.
Buddha.