Hi guys, been lurking around a while, but finally managed to get my account approved. Unfortunately it is at a time when I am having some major issues with my bike.

So recently I've done the following to my 2008 gs500:

Replaced fuel lines
Checked shim valves (All to spec)
Took out carb, couldn't get the covers off so left it (didn't have access to impact drill).

So I've got everything back together, and when I turn on the bike it immediately goes up to 6 rpm, wiht choke 7 rpm.
Not only that, but it sounds like something is "bubbling" inside the engine or carb. Theres also some massive backfire. I also see a bit of smoke coming out of the clutch side exhaust header connecting into the engine.

I thought I installed the throttle cables wrong, but I tested it and tested it and confirmed that I can hear the "snap back". I also visually inspected this before I put everything back in. I thought I may have turned the idle screw by accident, but after fully closing it (turned it clockwise, all the way) it was still idling at 6k, so no matter what I do to that idle screw it seems to remain on a high idle.

MY only guess is (from checking other posts) I got the camshaft timing wrong, (when I turned it to check the shims). Does anyone have a picture of how it should be? Can't seem to get a good one on google. Or whether anyone know what else I may have stuffed up. Getting ab bit worried that I am damaging the engine with the constant high RPMs and smoke!

(Note I didn't see any leaks at all, whether fuel or engine oil)

Thanks in advance!

Thanks! Do you know if I have to set it to a particular position after I'm done? I didn't take the chain off so i don't think the chain position has changed.

I remembered after I checked the last valve Top left (clutch side), I just cranked it a couple of times 360degrees. To get things lubed up and moving again.

Quote from: g2420hd on January 23, 2015, 10:27:40 AM
Thanks! Do you know if I have to set it to a particular position after I'm done? I didn't take the chain off so i don't think the chain position has changed.

I remembered after I checked the last valve Top left (clutch side), I just cranked it a couple of times 360degrees. To get things lubed up and moving again.

even if you took the chain out [impossible unless you crack the cases in half, or cut the damn thing..] it wouldn't matter. the RT mark will line up your transmission for the firing order. I and a few others have done a complete tear down lately. so its fresh in our brains.. [well right now I'm a bit high on paint fumes...  ]

Quote from: J_Walker on January 23, 2015, 10:57:50 AM

even if you took the chain out [impossible unless you crack the cases in half, or cut the damn thing..] it wouldn't matter. the RT mark will line up your transmission for the firing order. I and a few others have done a complete tear down lately. so its fresh in our brains.. [well right now I'm a bit high on paint fumes...  ]

So just make sure the RT mark is lined up like on the right diagram and I should be good?

Edit: Or are you saying it doesn't matter where the RT mark is? Sorry, out of my depth here atm, Baltimore G.S. makes it look deceptively easy +_+.

If you didn't remove the chain from the camshafts there shouldn't be anything wrong with your timing. Lining up the r-t mark is only for the purpose of measuring the clearances.

Turned the idle adjust clockwise? ... maybe it's my memory fudging out but.... doesn't that raise the idle turning it clockwise? ..  the hangy downy one that sticks out from under carbs yeah?

It's highly unlikely but possible that the cams are out of time if you were turning the engine over backwards while checking valves or if there is a problem with your cam chain tensioner so check the cam timing to be sure, only takes a couple minutes. Always turn engine clockwise as viewed from the right side.

To check cam timing put the rotor on the R-T mark as shown on drawing with notches on ends of camshafts pointed inwards towards each other.  If they point outwards turn the crank one full turn and cams will turn a half turn to point notches inwards.

With the rotor on R-T mark and notches inwards the little arrow marked 1 on the exhaust cam sprocket should point toward the cylinder head top finish as shown.  Starting with the chain pin adjacent to arrow 2 on the exhaust cam sprocket count 18 pins towards intake cam and the 18th pin should be at arrow 3 on the intake cam sprocket.  If it doesn't all line up this way timing must be corrected.

See my next post.

I think you should double check that you put the carbs all the way into the boots. Sometimes that last little bit doesn't want to give and if they're not fully planted  that'll cause a vacuum leak right at the engine port.

See Janx just posted and that's correct, clockwise on the idle adjustment should increase speed so turn ccw to reduce it.  Did you have carbs seperated when you had them off, sounds like they might not be synced to each other from way you describe.  Make sure they are set so throttle plates are parallel and operate together.  Could it be one carb is still open while other one has closed?  Check them out.

Quote from: Janx101 on January 23, 2015, 02:10:33 PM
Turned the idle adjust clockwise? ... maybe it's my memory fudging out but.... doesn't that raise the idle turning it clockwise? ..  the hangy downy one that sticks out from under carbs yeah?

Sorry, I meant anti-clockwise, but clockwise if you were lying on the floor looking at the screw. Bloody upside down screws these days...

Quote from: gsJack on January 23, 2015, 02:13:32 PM
It's highly unlikely but possible that the cams are out of time if you were turning the engine over backwards while checking valves or if there is a problem with your cam chain tensioner so check the cam timing to be sure, only takes a couple minutes. Always turn engine clockwise as viewed from the right side.

To check cam timing put the rotor on the R-T mark as shown on drawing with notches on ends of camshafts pointed inwards towards each other.  If they point outwards turn the crank one full turn and cams will turn a half turn to point notches inwards.

With the rotor on R-T mark and notches inwards the little arrow marked 1 on the exhaust cam sprocket should point toward the cylinder head top finish as shown.  Starting with the chain pin adjacent to arrow 2 on the exhaust cam sprocket count 18 pins towards intake cam and the 18th pin should be at arrow 3 on the intake cam sprocket.  If it doesn't all line up this way timing must be corrected.

See my next post.

Now that you mentioned it, I do remember freaking out when I accidentally turned it (probably no more than quarter turn if that) anti-clockwise. I'll check the timing.

Quote from: jtl216 on January 23, 2015, 02:17:24 PM
I think you should double check that you put the carbs all the way into the boots. Sometimes that last little bit doesn't want to give and if they're not fully planted  that'll cause a vacuum leak right at the engine port.

I'll check this, I do recall when I was screwing in my airfilter box to chasis screw on the left it was unusually tight. The one on the right went through easily so I thought I was good.

Quote from: gsJack on January 23, 2015, 02:22:52 PM
See Janx just posted and that's correct, clockwise on the idle adjustment should increase speed so turn ccw to reduce it.  Did you have carbs seperated when you had them off, sounds like they might not be synced to each other from way you describe.  Make sure they are set so throttle plates are parallel and operate together.  Could it be one carb is still open while other one has closed?  Check them out.

I took the T hoses off them if that's what you meant? Otherwise didn't take off any of the screws etc. Will look it up though.


Christ, looking back at it I seem to have screwed up in alot of places. Thanks for bouncing ideas guys will check the above points when I Get a chance and hopefully it will run ok again.

When I first put GenMar bar risers on my first GS500 about 15 years ago I rode uptown and as I was backing into a parking place my engine raced up to 6-7k rpm.  Turned out my choke cable which is normally routed around the left fork tube was being pulled open at full right lock of the bars.

Make sure your choke cable is fully relaxed when choke is off and not affecting your idle, in fact take it loose from the carb and make sure the choke slide thingy is fully pushed into carb body.  Someone else here had the choke actuator sticking recently holding the choke circuit open.

Quote from: gsJack on January 24, 2015, 06:05:05 AM
When I first put GenMar bar risers on my first GS500 about 15 years ago I rode uptown and as I was backing into a parking place my engine raced up to 6-7k rpm.  Turned out my choke cable which is normally routed around the left fork tube was being pulled open at full right lock of the bars.

Make sure your choke cable is fully relaxed when choke is off and not affecting your idle, in fact take it loose from the carb and make sure the choke slide thingy is fully pushed into carb body.  Someone else here had the choke actuator sticking recently holding the choke circuit open.

It turned out to be the idle screw, I got it idling at 1200 rpm, except ran into another problem with the choke.

Currently, if I turn it all the way on it will kill my bike.
f I turn it half way on, it will idle at it's proper RPM , 4000.
If I turn it on it will idle at 1,200. I didn't do anything to the choke except take it out and put it on and lube it. I rechecked it and it seems to be seated properly and sliding around properly, not sure if it is now oversliding or something?

After so much dicking around kind of don't want to open it up again this time, but is it alright if I just turn on the choke to half way instead when I start it ?

Quote from: gsJack on January 23, 2015, 02:13:32 PM
It's highly unlikely but possible that the cams are out of time if you were turning the engine over backwards while checking valves or if there is a problem with your cam chain tensioner so check the cam timing to be sure, only takes a couple minutes. Always turn engine clockwise as viewed from the right side.

To check cam timing put the rotor on the R-T mark as shown on drawing with notches on ends of camshafts pointed inwards towards each other.  If they point outwards turn the crank one full turn and cams will turn a half turn to point notches inwards.

With the rotor on R-T mark and notches inwards the little arrow marked 1 on the exhaust cam sprocket should point toward the cylinder head top finish as shown.  Starting with the chain pin adjacent to arrow 2 on the exhaust cam sprocket count 18 pins towards intake cam and the 18th pin should be at arrow 3 on the intake cam sprocket.  If it doesn't all line up this way timing must be corrected.

See my next post.

In theory the engine should work both forward and backwards if it's off, sparkplugs out, and you rotate it the wrong way because the cam lobes will still set be moving the valves. If he skipped a tooth on the cam gear turning it backwards, that's when the timing would go out - right?

Quote from: g2420hd on January 27, 2015, 06:05:24 AM

It turned out to be the idle screw, I got it idling at 1200 rpm, except ran into another problem with the choke.

Currently, if I turn it (choke) all the way on it will kill my bike.

<<I assume you mean it starts with the choke all the way on, fast idles however long never reaching 3-4k rpm, and then slowly dies out?  If so my 02 has done that for 100k miles of year around riding. But I slowly close the choke as it starts to die to keep it running.>>

I turn it half way on, it will idle at it's proper RPM , 4000.

<<That's more like my 97 was, started at fast idle with choke on and speed picked up rather quickly to over 3k rpm, I generally cut back the speed by starting to close the choke before it got to 4k.>>

If I turn it on it will idle at 1,200.

<<Not sure what you mean there?>>

I didn't do anything to the choke except take it out and put it on and lube it. I rechecked it and it seems to be seated properly and sliding around properly, not sure if it is now oversliding or something?

After so much dicking around kind of don't want to open it up again this time, but is it alright if I just turn on the choke to half way instead when I start it ?

So start on half choke and go ride, can't hurt anything I can think of.  No idea where you're at or what ambient temps you're dealing with.

Did you clean or replace your air filter when you had the air box and carbs off?  Something changed.  A couple years ago one cold winter morning my 02 wouldn't start so after cranking a bit with full choke I thought it might be flooded so I closed the choke and opened the throttle and cranked to clear it out and it wanted to start but wouldn't keep running.  Turns out it would start without choke and would keep running if I then gave it choke quick enough.  Had a very dirty air filter that raised carb internal vacuum while cranking and greatly enriched the mix without choke.  A new air filter and it was good to go again.

I personally had something similar in the beginning.
I cleaned out the tank, and carb, and thought my bike would run better, but as a result it ran worse.
Idle would slowly rev to 4-5k RPM.
That's when I read about unbalanced carburetors.
Turned out some drab (rust) entered and clogged one pilot jet. It was an easy fix. I have since installed inline fuel filters, and never had the same problem again.
I also purchased a $40 tool to check the vacuum on both carbs, to see if it is balanced.

Quote from: MeeLee on January 28, 2015, 03:49:34 PM
I personally had something similar in the beginning.
I cleaned out the tank, and carb, and thought my bike would run better, but as a result it ran worse.
Idle would slowly rev to 4-5k RPM.
That's when I read about unbalanced carburetors.
Turned out some drab (rust) entered and clogged one pilot jet. It was an easy fix. I have since installed inline fuel filters, and never had the same problem again.
I also purchased a $40 tool to check the vacuum on both carbs, to see if it is balanced.

Yep, a carb balancer tool is pretty much indispensable. The DIY ones are okay too if you want to risk getting water in your engine.

OP I don't think I read you balanced the carbs. I could reliably kill my bike by full choking it until I got the carbs in synch with each other. I would also check the operation of the cable in general. Make sure it completely closes the choke slide, and also make sure turning your bars full lock left and right doesn't cause the choke to magically engage.