Choke on Full idling low

[Clint21]

Hey guys.  Been noticing when starting my bike cold (choke on) its been taking a bit longer to get up to around 4500 rpm, like just a bit of a delay.  Today I went to start it and it wouldn't get above 2000 rpm (choke on).  New to wrenching around and not sure what's wrong / where to start.
Please help. 

Thanks,

Clint

[Courtice_GS500]

I've had the same problem with my 02'.

How is the air filter? Dirty or clean?
Is the choke moving freely? Not just the cable but the choke slide itself on the carbs?
Speaking of carbs are they clean? O-rings and diaphragms still good?
Have you checked for vacuum leaks with WD-40 or carb cleaner?
Have you checked the plugs? If so are they showing rich or lean?

Also don't forget to give bike details.
Year, miles, stock or aftermarket exhaust,air filter, jets etc....

My issue ended up being a horribly dirty air filter and my carbs just needed a good cleaning.

[Clint21]

Thanks Courtice, I got alot to check out it seems. 

Umm to the best of my knowledge, the only thing that is not stock is the Yoshimura exhaust pipe the PO put on.  As well as the handlebars but that's irrelevant. It's a 2005 F model and it has 11,XXX miles.

[Courtice_GS500]

If you go to the wiki section it has a detailed explanation of idle issues with an extensive troubleshooting list....

Start with the easy stuff ie air filter and vacuum leak then start looking into the carbs.

Maybe you'll get lucky and it will be something simple like mine was.

Make sure that choke slide is moving freely, maybe it's as simple as your choke not being fully "on".

Also just a thought/question, when the bike is at operating temp what is your idle set at.

Hopefully you find your issue in short order.

Let us know what you find.

[Clint21]

Alright cool.  Thanks for the reference.

Well the PO kinda screwed me.  Apparently did a "fenderectomy" and screwed the rear turn signals into the side panel fairings so i'm having a time trying to get that bad boy off which is apparently the first step in checking the air filter according to my Haynes manual.

As to your thought/q, i'm not sure.  I'll check once i get her running. Thanks again!

Clint

[Janx101]

Ummmm .... Air filter.... Lift seat off .... Unbolt rear of fuel tank .. Lift tank slightly... Look down and see air filter .... The inside of the filter is the 'dirty bit' .... Opposite to a car/truck

[Clint21]

Hey guys.

What I've done so far:
Still got a few items to take care of on Courtice's list, but wanted some input if possible.
My air filter is a foam one and i cleaned and oiled it. No dice.
Carbs look clean. Didn't mess with em because I'm new to tinkering and will tackle it only if necessary.
Also the choke slide on the carbs is moving freely.

Issue:
So my bike started up with the choke on but only idled at only 2000 rpm. I let it sit for a minute or so.  Then revved it.  Once revved, it idled at 4000ish rpm. Let it warm up a bit, then turned the choke off.  Bike idled at around 1000-1100 rpm with no choke, which is close to spec (could bring it up a hair).

Bike:
2005 F, Yoshimura Exhaust, Uni Foam Air Filter, rest is stock (I believe), 11,XXX miles.

Any input would be much appreciated.  Thanks in advance.

Clint

[Courtice_GS500]

When you say the carbs look "clean" are you saying that you opened them up and and checked to see if all the jets are clear?

Also since you have a Yosh pipe your carbs should have been jetted at some point.

What size jets are you running? Could be lean on the pilot.

There is info in the wiki for what your jet size should be and what your A/F screws should be at with what style of pipe and air filter
http://wiki.gstwins.com/index.php?n=Upgrades.Rejetting

If your still not sure PM Buddha, he helped me out

If you need a visual reference for the carbs check out

http://gstwins.com/gsboard/index.php?topic=56601.0

And don't forget to check for vacuum leaks

[Clint21]

No I haven't opened em up yet. I'll do that next time I have a chance to work on it a while. 

The pipe's been on there since I bought it last summer and I just now started having this problem.  Could the pipe change still be the issue even though the problem just cropped up?

Thanks for the links.  I'll be sure to check them out.

[Courtice_GS500]

If I had to take a stab at it I would say its your carbs or a vacuum leak.

Check for vacuum leaks everywhere and open those carbs up and clean the jets with carb cleaner and compressed air.

The pipe isn't neccassarly the problem I was just curious if you have checked the jetting.

All it takes is one vacuum leak or a clogged jet to make a bike run real crappy

Have you checked your plugs yet? I would venture a guess and say that they show lean.