So, I bought this 01 GS 500 a few weeks back as my commuter tool of choice.  When I bought it, the PO said he hasn't ridden it in a year.  Needless to say, the gas was garbage and the carbs were all gummed up.  When I got it home, i pulled the carbs and cleaned them with carb cleaner and compressed air.  Pu the m back on and she fired up.  took her for a spin and she has a hanging idle around 3000 rpm's, and she was running really REALLY lean and hot as hell! .  I checked for air leaks, but found none.  So I finally got back around to pulling the carbs last weekend, disassembled them, and dipped them overnight...cleaned them with carb cleaner and then compressed air.  I checked the float bowl height and adjusted the right one that was a little more than 1mm out of spec.  I had noticed each time that I took the carbs apart that the diaphram on one of the carbs was a bit out of shape inside the top.  I checked them both for holes, but couldn't find any.  I will post a few pics to see if anybody thinks this may be a problem.......I don't see it being pinched anywhere....





Whaddya think?

Have any chemicals come in contact with it? Looks like what happens to it when carb cleaner is used on it.......

mine looked like that  but it was ok

Quote from: Big Rich on November 15, 2011, 10:55:01 PM
Have any chemicals come in contact with it? Looks like what happens to it when carb cleaner is used on it.......

I am very careful when cleaning them and I know I didn't hit it with any carb cleaner......Maybe the PO did? If I flip it upside down inside the plastic carb top and push it in there tight, the shape is nice and rounded as it should be when there is vacuum in the carb........This condition is only visible when the top is of the carb.

I'll take twinrat's word on this one. It may not look perfect, but as long as it works.......

So your problem is a hanging idle and a po that neglected the bike.......does the cable get caught up on top of the carb? Any dirt or nicks on the slides? Varnish on the needle to prevent it from dropping all the way?

Quote from: Big Rich on November 16, 2011, 05:49:56 AM
I'll take twinrat's word on this one. It may not look perfect, but as long as it works.......

So your problem is a hanging idle and a po that neglected the bike.......does the cable get caught up on top of the carb? Any dirt or nicks on the slides? Varnish on the needle to prevent it from dropping all the way?

Cables are all clear of any obstructions/hangups.  I am pretty positive that it's either an air leak or super lean condition.  After dipping the carbs, I am positive that every orifice is cleared out and I can rule that out as the culprit.  Next is to put the carbs back on the bike, leave the airbox off, connect fuel supply, and fire it up. If I understand these CV Carbs correctly (forgive me, I am used to Flat Slide carbs) when I crack the throttle, I should be able to see both slides moving up in unison inside the carb body. I also will be putting on a new vacuum tube to rule out any issues with an old tube.  Keep the suggestions coming.....I am learning something every day!

Did you adjust the mixture screws on the bottom?

-Jessie

What is the year of the bike and the current jetting?

Quote from: BaltimoreGS on November 16, 2011, 04:50:07 PM
Did you adjust the mixture screws on the bottom?

-Jessie

Yup, started at 2 1/2turns out from seated.  The Haynes manual does not give you factory specs it only says "factory set" because of the brass plugs which the PO (an idiot might I add! But that is another story) pulled out.  The position of the screw does not seem to matter if I adjust it while the bike is idling........only tries to stall when turning it less than a full turn which makes sense.

Quote from: noiseguy on November 16, 2011, 05:45:19 PM
What is the year of the bike and the current jetting?

2001 GS 500, bone stock, stock jetting from what I can tell......I am having a hard time reading the numbers on the jets, the needle is stock factory too.  I should have time to fool with it more this weekend.

Best advice I could give is get new jets. If you can't read the numbers, then there is probably some varnish inside of them as well. Personally, I would take the opportunity to bump the pilots and the mains up a size from stock.

Quote from: Big Rich on November 16, 2011, 08:02:29 PM
Best advice I could give is get new jets. If you can't read the numbers, then there is probably some varnish inside of them as well. Personally, I would take the opportunity to bump the pilots and the mains up a size from stock.

Buddha has a "kit" that can be had correct?

Correct. Or if you have a motorcycle dealer near you, they "might" have the jets you need.

What jets would i need? I ride pretty much at sea level, have little interest in modding this bike (engine-wise), and will be riding it year round.

I have read on here that a bump up one size on the pilot and main makes a big difference, and leave the mid jet alone.....any thoughts?  How about the needle?  Is the stocker good enough?

Yup +1 on pilots and main - yes you need 20 pilots and 130 mains - small slotted round mains and VM style pilots.

I stock em, and $25 shipped in the US, $27 anywhere in the world.

I'd space the needle up a hair and set air screws to 3 instead of whatever random number they were set to. I have a O ring in the jet pack for lifting the needle if you dont have the washer above the e clip and I also have stainless allen head bolts for the bowls, you dont need those idiotic phillips head screws there any more than you need that brass plug.

Cool.
Buddha.

Quote from: The Buddha on November 17, 2011, 07:32:15 AM
Yup +1 on pilots and main - yes you need 20 pilots and 130 mains - small slotted round mains and VM style pilots.

I stock em, and $25 shipped in the US, $27 anywhere in the world.

I'd space the needle up a hair and set air screws to 3 instead of whatever random number they were set to. I have a O ring in the jet pack for lifting the needle if you dont have the washer above the e clip and I also have stainless allen head bolts for the bowls, you dont need those idiotic phillips head screws there any more than you need that brass plug.

Cool.
Buddha.

Thanks, that's what I needed.  I already swapped the float bowl screws for allen heads from Home Depot.  I do have the washer above the e-clip.....should i put it under the clip to raise the needle?  Will turn screws out to a full 3 turns and start there.

Just so I can document in my notebook, what size jet is the mid?

Yes that washer can be used to space up needle.

The min is a 60. The next size available is a 65, overkill unless you're getting lean symptoms after doing K&N and pipe and you are lean in the midrange with that washer under the clip.

Cool.
Buddha.

Quote from: The Buddha on November 17, 2011, 10:40:42 AM
Yes that washer can be used to space up needle.

The min is a 60. The next size available is a 65, overkill unless you're getting lean symptoms after doing K&N and pipe and you are lean in the midrange with that washer under the clip.

Cool.
Buddha.

Thank you sir  I will check my local shop for the pilots and mains....if they do not have them, i will be shooting you a pm

I suspect your running lean issue is not jetting, though you should do it anyway.

I'd back the screws out another turn... mine were too lean at 2.5 out, they are closer to 3.5 now.

For lean, check condition of carb boots and any vacuum lines, as well as all o-rings in place (I can see you still have the one's up top... those get lost often.)

You can check diaphragms by lifting them up, then letting them go with assembled carb. They should drop back down with a little resistance... if they snap down it indicates a leak. There's probably a way to vacuum check them... look at the carb circuit diagram. 

Last, when it's back together, check float level, for the hell of it. It's probably fine, but you never know. 

Quote from: noiseguy on November 17, 2011, 02:17:13 PM
I suspect your running lean issue is not jetting, though you should do it anyway.

I'd back the screws out another turn... mine were too lean at 2.5 out, they are closer to 3.5 now.

For lean, check condition of carb boots and any vacuum lines, as well as all o-rings in place (I can see you still have the one's up top... those get lost often.)

You can check diaphragms by lifting them up, then letting them go with assembled carb. They should drop back down with a little resistance... if they snap down it indicates a leak. There's probably a way to vacuum check them... look at the carb circuit diagram. 

Last, when it's back together, check float level, for the hell of it. It's probably fine, but you never know.

i don't think jetting is the issue either, but i might as well rejet while i have them off the bike. all of the o-rings look to be in good shape.  the slides seem to go up and down just fine...just as you said.  i will back the air / fuel screws out to 3 1/2 turns.  i measured the float heights....one was off by a little more tha 1mm, so i adjusted it accordingly.  also gonna check the valves to rule them out as a cause of this.