New bike High idle and has to run on pri

[Wannagofast83]

Just bought the bike and trying to sort out the issues that it has. It is a 2007 GS500f. I believe that it has been sitting for a while. Previously, I drained the gas out of it(and cleaned, had some water/ice in it) and put fresh in it. This required removing the tank. Not sure if this was an issue before because the gas was old and had some water in it, wouldn't run right. but now it has to run on prime to stay running. It will die is I leave it on. Also after it is warm and I reduce the choke, it will idle at around 6k. I took the petcock off and clean to make sure it wasn't clogged. It all looked good. I am not sure if both issues are related but am trying to resolve the high idle first and see if that changes the other problem. I have found info about the carbs being our of sync but I wanted to get other input before I start messing with stuff. Any ideas?

[The Buddha]

Both of those can be caused by 1 thing. Missing or broken vacuum line.
Cool.
Buddha.

[cbrfxr67]

Where pics? 

[Wannagofast83]

Where pics? 

Here it is!
https://photos.app.goo.gl/O38QltclmaRXJGst1

It was the brother in law's and he passed away exactly six months ago today.

[cbrfxr67]

ooh das nice

[Wannagofast83]

Both of those can be caused by 1 thing. Missing or broken vacuum line.
Cool.
Buddha.

Is there any diagrams that you know of for the carb setup? I found a few but they seem like earlier models.

[Kookas]

Both of those can be caused by 1 thing. Missing or broken vacuum line.
Cool.
Buddha.

Is there any diagrams that you know of for the carb setup? I found a few but they seem like earlier models.

This is the diagram for the latest carbs.
https://www.bikebandit.com/oem-parts/2009-suzuki-gs500f-carburetor/o/m19099sch650007

[Wannagofast83]

Both of those can be caused by 1 thing. Missing or broken vacuum line.
Cool.
Buddha.

I took the air box off and inspected the vac lines and didn't find any thing cracked or off. When I start it, it almost sounds like there is a leak towards the front of the engine but I am not sure what it is suppose to sound like. I took a video if you want to hear and give me your opinion. I also noticed that the spark plugs top look old as it was sitting outside. Could that cause this? I remove the plug wires and the engine stays running and is about the same when I remove the opposite wire. Seems like the carbs are in sync. Is there a vacuum diagram that I can use to check the route?

[Kookas]

Both of those can be caused by 1 thing. Missing or broken vacuum line.
Cool.
Buddha.

I took the air box off and inspected the vac lines and didn't find any thing cracked or off. When I start it, it almost sounds like there is a leak towards the front of the engine but I am not sure what it is suppose to sound like. I took a video if you want to hear and give me your opinion. I also noticed that the spark plugs top look old as it was sitting outside. Could that cause this? I remove the plug wires and the engine stays running and is about the same when I remove the opposite wire. Seems like the carbs are in sync. Is there a vacuum diagram that I can use to check the route?

Nah, if you had a spark issue, you'd find one or more of the following:
- not idling at all
- misfiring
- disconnecting one plug would lead to no change in RPM, disconnecting the other would cause the bike to stall

It also wouldn't really be affected by your petcock setting.

I'm told a good way to check for a vacuum leak is to spray WD40 at your engine intakes and see if it revs up, but I've never had a vacuum leak for it to work and I suspect it wouldn't work on an exhaust leak.

[mr72]

I took the air box off and inspected the vac lines and didn't find any thing cracked or off. When I start it, it almost sounds like there is a leak towards the front of the engine but I am not sure what it is suppose to sound like

Could be the intake boot o rings leaking or any other vacuum leak causing this. Thrrr are other possible causes too. I'd recommend just working the carbs over with the procedure in my blog, with adjustments for the mk2 carbs.

https://joshkarnes.blogspot.com/2017/09/fixing-common-gs500-carburetor-issues.html

[Wannagofast83]

I took the air box off and inspected the vac lines and didn't find any thing cracked or off. When I start it, it almost sounds like there is a leak towards the front of the engine but I am not sure what it is suppose to sound like

Could be the intake boot o rings leaking or any other vacuum leak causing this. Thrrr are other possible causes too. I'd recommend just working the carbs over with the procedure in my blog, with adjustments for the mk2 carbs.

https://joshkarnes.blogspot.com/2017/09/fixing-common-gs500-carburetor-issues.html

Are you saying that I should rebuild the carbs? They seem to run good otherwise. I took it all a part, removing the air box and didn't see any issues. Stumped on what the problem could be. Any one have any other ideas?

[mr72]

Are you saying that I should rebuild the carbs? They seem to run good otherwise. I took it all a part, removing the air box and didn't see any issues. Stumped on what the problem could be. Any one have any other ideas?

Did you follow the link I posted? Sounds like you didn't. I think it'll be clear what I recommend if you follow that link.

Taking the air box off is not going to be enough to evaluate the condition. The intake boot o-rings are the most likely thing to leak. To get to them you have to pull the carbs. Once the carbs are off it's trivial to take them apart, clean them, and replace o-rings in the carb along with jets if they have not been replaced (for size). And really this is a 2 hour job total top to bottom for someone who's done it before and probably half a Saturday if you are doing it for the first time. Go read my blog; it walks you through it.

[Wannagofast83]

Are you saying that I should rebuild the carbs? They seem to run good otherwise. I took it all a part, removing the air box and didn't see any issues. Stumped on what the problem could be. Any one have any other ideas?

Did you follow the link I posted? Sounds like you didn't. I think it'll be clear what I recommend if you follow that link.

Taking the air box off is not going to be enough to evaluate the condition. The intake boot o-rings are the most likely thing to leak. To get to them you have to pull the carbs. Once the carbs are off it's trivial to take them apart, clean them, and replace o-rings in the carb along with jets if they have not been replaced (for size). And really this is a 2 hour job total top to bottom for someone who's done it before and probably half a Saturday if you are doing it for the first time. Go read my blog; it walks you through it.

I decided to remove the carb and ordered the carb kit. I have never rebuild/cleaned a carb but going to give it a chance. I took one bowl off and it looks pretty clean but I am going to rebuild any ways.


I found a cap that is cracked and wonder if it is the cause and if I should replace it. The other carb has a vacuum line connected to it.


Anyone have any pointers?

[Wannagofast83]

Can you help make sure that I know what all these are and their function?

[mr72]

Replace that cap and follow the instructions on my blog post. You likely don't need some stuff in a carb kit and you probably need several o rings that are not always included in a carb kit.

Don't spray carb cleaner on it until you have removed all rubber parts including the diaphragm from each carb.

Check the intake boots.

It's possible most of the problem is that cracked cap. It's worth it to fix all the other stuff since most of the work is getting the carbs off.

[Wannagofast83]

It is my understanding that I will not have to sync the carbs afterwards, is that correct? Just adjust the air/fuel ratio.

[mr72]

That's correct, as long as you don't mess with the balance screw.

That doesn't mean they are guaranteed to be balanced, just that it's not strictly necessary to rebalance them. They will be no worse than they were before if you don't rebalance.

[Wannagofast83]

I have the carbs apart and I am a little confused. There is more o rings than I can find. Is the big one part of the choke and do you unscrew the black plastic screw

Here is the similar kit that I got.

[tobyd]

The tiny one fits under the black cover around where the vacuum outlet is.

I also certain the larger one fits in the slider gubbins, i have the older pre 3-stage carb though.
http://faq.f650.com/FAQs/Photos/CarbnJetPhotos/SlideVenturiOringIdleScrew.jpg

[Wannagofast83]

How do I get the main needle our of the diaphragm/slide? Does it screw or pull out? I think that is where my last o-ring goes.