Need ideas? Project bike won't run....

[craigs449]

Bought a 2001 GS 500 for cheap because it had sat for a year and would not start.  It has less than 15,000 miles on it.  Brought it home, drained the fuel, flushed the tank, cleaned the carbs really good, and got it fired up.  It ran really lean, did not want to stay running, and was hard to start after continuous stalling.  Also exhibited a hanging idle.  Pulled the carbs off again and dipped them overnight, pulled the valve cover to check the valves.  All of the valves were too tight.  Ordered a valve shim kit and the tool.  Once I got it, I adjusted them all within spec.  Checked the float heights and made sure they were within spec (13mm +/- 1mm).  Reassembled the bike and started it up. It ran briefly, then stalled.  Would not start, and it was pushing fuel out of the intake side of the carbs and into the airbox.  After cranking for a few minutes, I ammased about 4 ounces of fuel from the airbox drain tube. 

Today:  Pulled the carbs and adjusted the floats really low (thinking they were allowing too much fuel in, as evidenced by the fuel dump into the airbox) I adjusted them to 15.8mm left carb, 15.6mm right carb.  Tried starting again and it started briefly, them stalled.  Still have fuel dump, but not nearly as much.  Pulled the plugs,,,,both were sopping wet with fuel.......plenty of spark though.  Pulled the valve cover again.  Checked the valves with the following results:  Right intake - .08mm, right exhaust - .05mm, left intake - .08mm, left exhaust - .012mm......I reshimmed the right exhaust to get to .12mm. Buttoned it all back up and fired it up.  It ran a bit longer, but eventually stalled and started dumping fuel back into the airbox (seemed to be more from the right carb than the left?)  Fuel is only blowing back when cranking the starter, not when sitting (leads me to believe the float height is OK).  I am hoping that I just had a bad read on the valves the 1st time, and the head is not eating the valvetrain starting with the right exhaust valve........


I have about had it with this bike!  I can tear my 2 stroke down with my eyes closed, but this thing is killing me!  Any help/suggestions?

As far as I know, the PO has never had the valve cover off, and never did anything other than change the oil. 

[Tombstones81]

did u try different settings on the petcock?

that could be letting too much fuel in.
it did for mine, but not as much as your describing.

[craigs449]

I have tried Prime, and also "run".....I will try reserve in a bit.  Thanks for the suggestion.  But even if the petcock is letting too much fuel into the carbs, the carbs should meter out the proper amount for the combustion chamber right?

[Tombstones81]

check the float height correctly?
http://gstwin.com/float_height_check.htm

could also be a stuck float

[craigs449]

check the float height correctly?
http://gstwin.com/float_height_check.htm

could also be a stuck float

I checked them per the manual while I had them apart.  I don't think it's a stuck float because it does not overflow when I am not cranking the starter regardless of the petcock position.  Another wierd thing, I tried it in the reserve position, but the petcock under the tank was off...the bike idle pretty decent, but if I blipped the throttle, it would stall........no fuel dump though.......I turned the petcock to the on position, and it was back to the way it had been.....stalled and dumped fuel when cranking.

[craigs449]

Anybody know wher I can pick up a carb rebuild kit for this bike (2001)? I can only find the older (2000 and previuos years)......Also, will a carb from a newer GS (With TPS) work on this bike?  Just leave the TPS unplugged?

[craigs449]

check the float height correctly?
http://gstwin.com/float_height_check.htm

could also be a stuck float

I tried this method, but I get differing readings on the right carb (problem side..)  One time it will show the appropriate height, the next time it will show about an inch above the bowl height.  The left side carb shows the appropriate height (at the base of the bowl).  I guess the wierd readings from the right side carb means the float might be sticking?  Sometimes stuck, sometimes not stuck?

[craigs449]

Update.....

pulled the vacuum tube from the carb and turned the petcock to Prime.  She fired up and idled, however, she did a bit of muffled "psstttt" every once in a while...each time this happened, the idle went down and most of the time she stalled.  I would get her running again but only with the choke off and no throttle input.  I did this for about five minutes, letting it idle until she stalled, then restarting her.  I noticed a bit of condensation (water only) dripping from the forward end of the silencer, but there is plenty of backpressure coming from the exhaust end (the bike has been in my garage since I brought it home, so I don't know about this?)?  Now...here's where it gets wierd...I pulled the plugs to be sure that I was still getting spark on both sides....the left plug was dry and pretty black, the right plug was wet with fuel.  I noticed when I pulled the plugs that the left side of the jug was hot, and the right side of the jug was not nearly as hot as the left!!!!!!  I assume this means that the right side carb might have a sticking float, causing too much fuel to be pushed into the combustion chamber, causing the "PSSDTTT" sound as it puts out the spark and causing the idle to go down and causing the stall.  Therefore the right side has not had nearly as much combustion as the left side and it is not as hot as the left accordingly?    Somebody tell me That I am wrong or right here......Please?

[Tombstones81]

if only the right carb is showing that. (getting too much fuel at times)
then I would guess so.

never had a float problem and never physically dabbled in it before.
only had petcock problems and rejetted and partially rebuilt my carbs. (seals, float needle etc)

heres another thread with float problems.
might find something in there that would help.
http://gstwins.com/gsboard/index.php?topic=56565.0

(edit)
sounds spot on.
Too much fuel on the right.
only thing I personally know that could cause this, is sticking floats if they are adjusted properly.

another possibility is if they are out of sync and your right side is open alot more then the left.
just incase your not fluent with them fully, im talking about the 2 ports there that go into the boots into the motor.
if the flaps are not even, i do believe it will cause ones side to get more fuel.
and to adjust that is the Balance screw labeled in the pic, if you didnt know already.

[Paulcet]

Flat/cracked o-rings around the float needle seats will cause fluctuating fuel levels, as will intermittently stuck floats (open).  Look closely at the float needles, they should be conical shaped, no step or groove in the rubber tip.

[Tombstones81]

Heres a useful sticky thread with everything on the carbs labeled that many usually miss.

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

once again, just incase your not fluent with everything in the carbs.

[Big Rich]

Have you checked for a strong spark on each side? Battery in good shape?

[craigs449]

Flat/cracked o-rings around the float needle seats will cause fluctuating fuel levels, as will intermittently stuck floats (open).  Look closely at the float needles, they should be conical shaped, no step or groove in the rubber tip.

Big rich....Very strong spark on both sides......I just think the right side is dumping too much fuel into the Com Chamber, causing the spark to go out.  Kinda making sense to me now....

Pualcet.....When I cleaned them, I looked at them closely, they looked good, as did the float bowl seats.  Even put the float needle in the seats and tried to blow air out of them to no avail.......


Tombstone, all the suggestions are useful....I know my way around carbs, but each reminder ensures that I double check each portion...I appreciate every suggestion that has been made, regardless of how general it may sound....



i appreciate everyone that has thrown anything out there...alot of times, I just need to put all the info out there to realize what the hell is going on and you guys giving suggestions helps out alot.........  Now I need to find a rebuild kit for the 01 carb...anybody know where to find such an animal?

[Big Rich]

If the float isn't sticking, I've seen them sink before too. Don't think it's a common problem on the GS though. I may have missed it, but is the choke sticking somehow on the right side? That could provide too much gas as well.

I know you are checking the valves, but have you done a compression test on each side?

[craigs449]

If the float isn't sticking, I've seen them sink before too. Don't think it's a common problem on the GS though. I may have missed it, but is the choke sticking somehow on the right side? That could provide too much gas as well.

I know you are checking the valves, but have you done a compression test on each side?

The choke cable/linkage seems to be moving fine looking at it from the outside......How do I check that it's working properly on the inside? I have not done a compression test yet......really hoping that the rings aren't bad on the right side (crossing fingers). I am leaning towards a float issue in the right side carb...either old (I have pulled the needle valve seat and inspected the O-ring which did look a bit old) o-rings in the needle valve seat, or the needle valve itself.  Gotta find a rebuild kit pronto....

[Paulcet]

Here's what I did for o-rings: take the old ones to a hardware or auto parts store who carries o-rings. Try to match sizes. Because the old ones are probably flat, get the next size up or down (i got both sizes, just threw away about $0.75, which is chapter than going back to the store).

[craigs449]

Here's what I did for o-rings: take the old ones to a hardware or auto parts store who carries o-rings. Try to match sizes. Because the old ones are probably flat, get the next size up or down (i got both sizes, just threw away about $0.75, which is chapter than going back to the store).

Good idea.  I guess since no one makes a carb rebuild kit for this bike, I will have to order OEM for the Needle valve assembly? 

edit:  from the pics i have seen, it appears that everything in the float bowl from a newer (2002-2009) model looks to be exact.  Are the carbs the same, just the new ones have TPS? If so, I should be able to find a rebuild kit for one of those new ones and use it for mine.....

Also, when I pulled the carbs apart yesterday, i put the floats in a bowl of gasoline to see if the were leaking/cracked (If they were, they would fill with gas and sink).  Both of them continued to float after 10 minutes or so, ruling that out as an issue.

[Tombstones81]

Good idea.  I guess since no one makes a carb rebuild kit for this bike, I will have to order OEM for the Needle valve assembly? 

http://www.bitzforbikes.co.uk/Carburettor_Repair_Kit.-ref-12525-9534-2537-.html

your welcome  (I think) haha

£23.95
Suitable for:

Suzuki GS 500 2001 Onward (K models) (K1 2001)

the (I think) was because I have no idea what the K models are

(edit)
heres the entire listing for the 01 K model I was lookin at for ya
http://www.bitzforbikes.co.uk/Suzuki/GS_500_2001_Onward_%28K_models%29/K1_2001/all

http://www.bitzforbikes.co.uk/Carburettor_Diaphragm.-ref-12549-9534-2537-.html
^^ Diaphragm

Needles when I needed them, I simply ordered those from an OEM site and the rebuild kit from another.

[craigs449]

Good idea.  I guess since no one makes a carb rebuild kit for this bike, I will have to order OEM for the Needle valve assembly? 

http://www.bitzforbikes.co.uk/Carburettor_Repair_Kit.-ref-12525-9534-2537-.html

your welcome  (I think) haha

£23.95
Suitable for:

Suzuki GS 500 2001 Onward (K models) (K1 2001)

the (I think) was because I have no idea what the K models are

(edit)
heres the entire listing for the 01 K model I was lookin at for ya
http://www.bitzforbikes.co.uk/Suzuki/GS_500_2001_Onward_%28K_models%29/K1_2001/all

http://www.bitzforbikes.co.uk/Carburettor_Diaphragm.-ref-12549-9534-2537-.html
^^ Diaphragm

Needles when I needed them, I simply ordered those from an OEM site and the rebuild kit from another.

Thanks, I don't know about shipping to the US from the UK.

Although that does answer a previous question about carb part compatibility.  This kit is listed as a rebuild kit for the 2001 (K1) and newer bikes. So I can find, say, a rebuild kit for a 2005 GS 500F and it would work for my application....thanks for the info.

[craigs449]

Found this info on the web while trying to find a compatible carb rebuild kit for my 01'..

Here are the different float valve part numbers from a certain parts website:


1989-2000:
13370-02D00  (replaces 13370-44B00)

2001-2002:
13370-33E80

2004-2006 (K4,K5,K6)
13370-04F00