Trouble with 2007 gs500f

[Gcook57]

Hello having trouble with my 2007 GS500f , hard starting won't idle I clean the carbs out and blew out the Jets I got it running ok but it seems to have no power and no mid-range I would estimate 0 to 60 in about 10 seconds I also found no vacuum going to tnohe petcock would lack of vacuum affect the performance of the carburetors any help would be great

[Watcher]

An open vacuum port (vacuum leak) will DEFINITELY cause poor running conditions.

There should be a vacuum line going from the petcock to a little nipple on the side of one of the carbs near the top.

Otherwise if you are unsure of where the vacuum leak is you can fill a spray bottle with water and mist it around the carbs while the bike is idling.  A dip in idle will indicate that the engine inhaled water.

[Gcook57]

 thanks for your comment but it seems like I have no vacuum at all going anywhere I noticed two tubes on the front of the cylinders going up to something that initiates the total vacuum line I mostly work on cars and know that you only have vacuum at tile  how does the bike produce constant vacuum at all RPM would this affect the performance having no vacuum at the carburetor

[Watcher]

thanks for your comment but it seems like I have no vacuum at all going anywhere I noticed two tubes on the front of the cylinders going up to something that initiates the total vacuum line I mostly work on cars and know that you only have vacuum at tile  how does the bike produce constant vacuum at all RPM would this affect the performance having no vacuum at the carburetor

What, only vacuum at idle?  Who told you that BS?

Vacuum is a product of the pistons during intake stroke, and the only force that draws fuel and air through the carb and into the cylinder.  Some of this vacuum is tapped off and used to operate accessories, in the case of the GS it's typically the petcock, in the case of cars it could be much more, for example, the wipers on old cars and more commonly the brake-booster just before the master cylinder.

Seeing as you have a 2007 you should have vacuum lines going here and there and every which way because of the emissions system.

Have a look at this.

[Gcook57]

I guess what I should have said is that on a car you only have full vacuum at idle but that's besides the point it seems like I'm getting no vacuum at all from the pair valve the hose that comes off the pair valve teys directly to them petcock and I get no vacuum here with the engine running.  so I have to run it on Prime to get fuel flow I got the bike to idle good but it's got very bad performance would not having vacuum to the carburetor affect the performance

[Watcher]

If there is no vacuum getting to the petcock but there is a line attached to it then either there is a vacuum leak somewhere up the line or the vacuum port or an attached line is clogged.

Try the spray bottle trick and if that yields no results I'd start taking lines off piece by piece and making sure they're clear.

Any air being drawn in from somewhere other than the air-filter/carb "mouth" means that air is not picking up fuel.  You'll have poor performance.

[Gcook57]

 there are no vacuum leaks in the hoses I'm getting no vacuum from the pair valve besides affecting petcock will this affect the performance of the carbs

[Gcook57]

Does anyone know where the vacuum source is on a 2007 vs 600 f l took the carbs off and don't know if l got the lines hooked up correctly, l thought l traced the vacuum lines back to the pair valve but the more l research l am beginning to think this pair valve might not be the vacuum source, after cleaning the carbs (bike has only 4 k miles) the bike has no vacuum to the pet chicken but l can run it on prime but it's hard to start and is very low on power seems to idle ok sometsometimes ,backfires when l twist the throttle sometimes when l removed the jets ( 2 on each carb) l noticed the jets  were identical except for the size of the hole in the jets so l put the bigger jet  on what l think is main jet ( the one in the middle of the carburetor that sticks down in the bowl and the smaller one in the other hole.l am wondering if thsts backasswards and why it runs crappy and probably goes 0 - 60 in over 10 seconds  it's seemed run better with the airbox just connected l am getting  discouraged any help would be appreciated

[Watcher]

That should be a 3 jet carb and all 3 jets should be different types.

Can you take pictures of what you're working with?

Vacuum source is pictured on that diagram I posted, the line coming off the side of the carbs above the TPS.  It runs to a T which then runs to the pair valve and petcock.

[ajensen]

Step one: make sure the valves are not too tight--a little loose is much better than a little tight.
Step two:  make sure that you have the correct jetting for whatever air filter is on the bike
Step three:  take off all the un-necessary vacuum lines. A good plan is to have a hose run directly from the right carb mount to the petcock.
.
My '06, which I bought a couple of months ago, runs really well now that I have adjusted the valves and cleaned the carbs--really thoroughly.
Let us know how it works out.

[Gcook57]

Thank everybody for all your help

[rg500gamma]

Hi  are you in los angeles California ? 

[Gcook57]

Detroit

[Gcook57]

Can anybody identify the two black electric vacuum devices on the right side of the carb l thincking the one without the vacuum lines is the TPS I'm not sure what the other one is . Do l really need all this
Stuff on the carb .l would like to eliminate all unnecessary bs
I'm getting no vacuum to the pet chicken and the are no leaks in the lines.can l run a line right from the vacuum source to the pet chicken and eliminate  all the other stuff .What does the TPS do?

[Watcher]

That image I posted should answer most of your questions, but can you take pictures so we have a better idea of what it is you're talking about?


If you aren't in CA you can take off the charcoal canister.  Pretty much everything else is necessary to the operation of the carbs.
The TPS helps with the actuation of the vacuum slides in the carbs which are those two valves at the top of the carbs.  You need this for the carbs to run properly.


I feel like you aren't taking the advice I'm trying to give you, either.  Vacuum source is the nipple on the side of the carbs, if no vacuum is getting to the petcock there is either a leak somewhere up the line or a clog somewhere up the line.
If you did the spraybottle trick and didn't find any leaks you have a clog.
Start taking the lines and pieces off one by one, starting at the petcock, and work your way up the line testing if each piece will flow air.
You'll find the problem piece eventually, and the diagram will help you put it all back together.

Do this, and then come back here and tell us what you found.

[Gcook57]

I tried the spray bottle trick& no vacuum leaks, l get vacuum from the right hand carb nipple to the electrical device located on the bottom of right side carb  but nothing coming out,essentially no vacuum to anything after that l am trying to post a pick but it won't let me

[Sandgroper57]

Could it be your vacuum lines fitted incorrectly? I just checked mine by torchlight. There is a short section of tube from the RH carb vacuum outlet to a T piece. One side of the T goes to the petcock, the other down to the vacuum controller at the bottom. The line to the petcock has a larger outer diameter than the other tubing. If you have vacuum at the controller then you should have vacuum at the petcock.

My setup is a little different to the pic Watcher posted as Australian bikes didn't come with the pair system or charcoal canister.

Will take a photo in daylight tomorrow and post it if you think it would be of any assistance.

[Gcook57]

Can anyone tell me how the electronic vacuum  control valve  works on a 2007 gs 500f and are they know for going bad. My bike has no midrange or top end .l cleaned the carbs checked valves and checked for vacuum leaks...its kinda like the secondaries on a four barrel carb are not opening??

[Sandgroper57]

Can anyone tell me how the electronic vacuum  control valve  works on a 2007 gs 500f and are they know for going bad. My bike has no midrange or top end .l cleaned the carbs checked valves and checked for vacuum leaks...its kinda like the secondaries on a four barrel carb are not opening??

You are losing vacuum then, that is what makes the slides rise, hence no midrange or top end. The LH carb also has a vacuum outlet but that should be capped off. Check the cap is in place and not cracked or perished. It is in the same place as the RH carb but behind  the choke linkage and difficult to see. Also is a shorter stub than the RH.

As far as I can find out, the vacuum controller is for lowering emissions. When the throttle is shut whilst decelerating the valves at the top of the carburetors are opened and allow atmospheric pressure to push the slides down. Shouldn't be too difficult to bypass the whole thing if you are so inclined.