Hello dear all,

hope you guys can help me as I am an a newbie mechanic with no experience and lots of problems

ok, I got 1990 gs500. bike was sitting for a couple of years. now I am trying to bring it back to life. When I started it the first time it started but was working unevenly and died eventually. so I cleaned the carbs and put it all back together, or at least I hope so it sounds much better and doesn't seem to die right away, and there are no shotgun shoots from my exhaust system anymore, but I got a few problems.

First of all, there are two t-shaped tubes between the carbs, one plastic at the bottom and one rubber at the top. the bottom one as I understand is a fuel line, but as for the top one I couldn't find any info, so I don't have anything plugged to it. there are no other tubes with free ends in the bike so I am not sure what to do with it. Any info is appreciated

Secondly, the right carb doesn't seem to work. If you pull out the cord going to the right spark plug the bike still runs, although not as smooth), but when you unplug the left one (with the right plugged in) the bike dies. What can it be?

I'd appreciate any info as I am desperate to ride, but not rich enough to spend money on somebody to work on it. Looking forward for your replies.

the top "T" is a vent/drain tube.  Look here for a routing diagram:

http://www.bbburma.net/FuelHoseRouting.htm

Check if there is spark to both cylinders (lay spark wire against bike and engage the starter... watch for spark on both sides).  If no spark in one cylinder, check the ground wires on the battery.  Reportedly, there is a big thick ground wire, and a thin ground wire, crimped to the big one.  If the thin one loses conductivity with ground (such as if the battery pulls on the ground wire), then one cylinder will cut out.  (not tested by me)

Quote from: Rema1000...If no spark in one cylinder, check the ground wires on the battery.  Reportedly, there is a big thick ground wire, and a thin ground wire, crimped to the big one.  If the thin one loses conductivity with ground (such as if the battery pulls on the ground wire), then one cylinder will cut out.  (not tested by me)

Hasn't been tested by me either, but I can confirm this report of the wiring because I just finished the frame level rewiring of my 90 project. The big ground wire (aka - black, negative lead) has a smaller wire crimped on it near the connection to the battery. The other end of the large ground wire is connected to the engine case just forward of the rear brake master cylinder. This location is difficult to get to and check.

We have had several posts about "one cylinder firing symptom" and I believe Srinath has seen a poor small ground wire connection cause this. It makes sense because the ignitor module (aka - black box...mounted on the left side of the battery box) needs a direct connection to the negative battery. "Frame grounds" are too iffy to depend on for clean electronic operation. Too much vibration, dirt, moisture, etc.

It is always a good idea to go over ALL the electrical connections on a project bike. It can save headaches later.

thanks guys for the prompt replies, but
1) ray: looking at the diagram I somehow have a short tube infront and long in the back (that is it looks like 1 and 2 are switched in my case, although the shutoff switch is on the other side like the diagram). As for the top tshape I guess I just lost the hose somewhere, but since it doesn't connect to anything it should not matter at the moment.
2) rema and star: I took out the spark plugs and they seem to be sparking all right.

and to my disappointment the engine still dies after a while, and it won't run with choke full open even for a second.

also, can it be that one carb works "just a little bit"? Because when I unplug the right carb the sound still changes, like there's less power (although the bike still runs for a while), but then again when you unplug the left one it just dies

now about the "auxilary ground", first of all thank you for giving me an idea on the key words to feed the search system. As for the application of the solutions.. all my wires are wrapped together in a black tape so it's impssible to judge where that ground wires go, I am no mechanic yet, so please tell me if it's safe to unwrap them, whether I need it, etc.

Also if I find a dirty/rusted connector, what's the best way to clean it and prevent from further rusting? I saw people mentioning electrical grease, is it available at auto stores or where do I find it? as for cleaning do I use sandpaper?

And finally the auxilary ground in my case is two black and white wires. I did my best trying to locate where they might be going.. I found one black and white connector just hanging next to the flasher, not connected to anything and there seems to be nothing to connect it to. I was unable to locate where the other one goes.. Any ideas on the loose connector? what do I do with it? I figured that might be the reason for my troubles, am I right?

I'm not sure about the loose connector.  :dunno:

Since you're desperate, perhaps you could work your way through the first 2 pages of this thread?  I am especially interested in your resistance results for the worksheet near the bottom of the 2nd page....

thanks for the info Kerry, but just like the guy in the thread I am new to using a multimeter. Do I understand it right that I just unplug the coil on both sides and connect one side to one multimeter connector and the other to the other and just write down the number it gives me? what do I compare it to? because in the manual to the multimeter it says use the setting just above what you expect to read.. so what do I expect to get?

also about running on one cylinder, the other one actually kind of works... as long as you open the throttle, otherwise it dies after 2-3 turns. Does it mean that it is not an electrical problem?

and finally my turn signals don't blink, just just turn on or off, can it affect how the bike runs or am I getting too paranoid?  

Quote from: Soaring................ if I find a dirty/rusted connector, what's the best way to clean it and prevent from further rusting? I saw people mentioning electrical grease, is it available at auto stores or where do I find it? as for cleaning do I use sandpaper?

Yes, you can use fine sandpaper to clean the contact surfaces.  Use dielectric grease, available at auto parts stores, when you fasten the electrical connections.  This will keep moisture out of the connection and avoid corrosion.

Quote from: Soaring............. I found one black and white connector just hanging next to the flasher, not connected to anything and there seems to be nothing to connect it to. ...........

This wire is not used. Just ignore it.

Quote from: Soaringnow about the "auxilary ground", ........... all my wires are wrapped together in a black tape so it's impssible to judge where that ground wires go, I am no mechanic yet, so please tell me if it's safe to unwrap them, whether I need it, etc.
................
And finally the auxilary ground in my case is two black and white wires. I did my best trying to locate where they might be going.. ................ I was unable to locate where the other one goes..............

I assume you are referring to the small black-white wire attached to the large black wire at the neg (-) terminal of the battery.  That wire splits off into two black-white wires.  One of them is a direct connection to the regulator/rectifier. The other is the return path (ground) for all the other stuff on the bike like lights, horn, start ckt.  Test the continuity of all the black-white wires by using an ohmmeter.  Disconnect the wires from the neg. (-) terminal of the battery.  Then clip one lead of the ohmmeter to the disconnected (-) wire.  Then using the other test probe, test all the other black-white wires that you can find for continuity (zero resistance).  You don't have to unwrap the cable to do this.

Quote from: Soaringjust like the guy in the thread I am new to using a multimeter. Do I understand it right that I just unplug the coil on both sides and connect one side to one multimeter connector and the other to the other and just write down the number it gives me?

Yep, along with the range that the selector switch is set to.  (Just in case.   )

Quote from: Soaringin the manual to the multimeter it says use the setting just above what you expect to read.. so what do I expect to get?

I thought the numbers were fairly obvious in this post ... and this one ... and this one.  :dunno:

Quote from: Soaringalso about running on one cylinder, the other one actually kind of works... as long as you open the throttle, otherwise it dies after 2-3 turns. Does it mean that it is not an electrical problem?

No ... that is how mine acted for 5 months, until I found the bad connection to one of the signal generator coils.  (But there's not enough data yet to say that it's definitely an electrical problem, either.)

Quote from: Soaringfinally my turn signals don't blink, just just turn on or off, can it affect how the bike runs or am I getting too paranoid?  

I can't think of a way that a faulty turn signal circuit could affect how the engine runs.  Sounds like you might have a bad blinker unit or even a bad bulb or connection.  (I'll leave those electrical details to John Bates or another volunteer.)

Quote from: Soaring.................. my turn signals don't blink, just just turn on or off, can it affect how the bike runs or am I getting too paranoid?  

The turn signal ckt does not normally affect how the bike runs. Only if a prior owner had messed with the ckt could this happen.  If the bulbs light but do not blink then the relay is bad.  Get a Wagner 552 (or equivalent) at your local auto parts store.

kerry,

ok, sorry I was a little sloppy about the threads, just wanted to make sure I am not going to break anything. Now, I got these readings:
coils: left 22.7, 5.1
right 22.5 5

so I figured these are ok

I looked under the suzuki cover, everything clean there

I tested the wires in the 4 wire connector got got 350 and 349

so I figured these are ok too.

Now I cannot locate the three wire connector you were talking about. the links in the thread you referred me to point to nonexistent threads, so I cannot see what you are talking about...

looking forward for more wisdom from you and thanks a lot for helping me out, I feel way more confident now

sorry kerry, found the damn thing right after sending the previous message, was hidden behind a lot of stuff.. anyway, this one seems bad, reads 1854 and 1837 on a 2000 ohm setting. what is the next step?

also, b/w 3 and 4 connectors get zero resistance and b/w inp and outp of 4 connector get zero resist, so looks like my problem is the 3 wire connect... what do I do?

Sounds like you found the right connector but here's the photo from the missing thread anyway.  Four-wire connector on the left, 3-wire connector (opened) on the right:



To help me get the clearest picture of what you've got, could you copy and paste the checklist from my last post on page 2 of that thread, and fill it out?

Meanwhile, my post just previous to that one addresses the "what do I do now?" question.  Once you're SURE that there is a problem in a connector or a wire, you go about bypassing the problem area with a new connector and/or length of wire.

ok, now  I htink I got confused ..

3 wire conn: these 18XX numbers are for the side of the connector that goes to the black box (ignition control?) the other end reads 351 351

4 wire conn: the wires that go down (to signal generator?) read 351 352, the other end (that goes and gets wrapped together with other wires) reads 1836 and 1854

so it looks like I am fine here.. or am I still confused?

If I'm picturing everything right, it does sound like you are OK as far as the signal generator circuits are concerned.  With the 4-wire connector snapped together you should get pretty close to the same readings from the opened 3-wire connector.

350 / 349 sounds pretty close to 351/351, and they're all well within spec.  

You've just eliminated one of the possibilities!  


Now about your ignition coil readings:

Quote from: Soaringcoils: left 22.7, 5.1
right 22.5 5

If (as I assume) you got the 20-ish readings on a high-ohm scale and the 5-ish readings on a low scale, you're OK here too.

Hmmmmm.

ok here's what I think I've got:


3-wire connector
MAKE SURE you're taking the reading on the half of the connector that's attached to the wires that go DOWN to the 4-wire connector, and not back UP to the wiring harness!

IF I GOT THE RIGHT SIDE OF THE CONNECTOR (THIS SIDE GOES WITH OTER WIRES):
Between Black/blue & Brown: __351___ ohms (Should be 240-420)
Between Black/blue & Green/White: __351___ ohms (Should be 240-420)
THE OTHER SIDE (THAT GOES INTO  THE BLACK BOX RIGHT NEXT TO IT, IGNITION CONTROL?) READS 18XX (LIKE 1836 AND 1843 OR SOMETHING)

Wires between the 3-wire connector and the 4-wire connector
Touch your test leads to the little metal crimpers where the wires attach to the connectors.

Black/blue wire: __0___ ohms (Should be near 0)
Brown wire: __0___ohms (Should be near 0)
Green/white wire: __0___ ohms (Should be near 0)



Between input and output points on (snapped together) 4-wire connector
Touch your test leads to the little metal crimpers where the wires attach to the connector.

Black/blue wire: _0____ ohms (Should be near 0)
Brown wire: __0___ohms (Should be near 0)
Green/white wire: __0___ ohms (Should be near 0)



Between different wires on the (popped apart) 4-wire connector
MAKE SURE you're taking the reading on the half of the connector that's attached to the wires that go DOWN to the signal generator coils, and not back UP to the 3-wire connector!

IF I GOT THE RIGHT SIDE OF THE CONNECTOR:
Between Black/blue & Brown: __351___ ohms (Should be 240-420)
Between Black/blue & Green/White: __351___ ohms (Should be 240-420)
THE OTHER SIDE READS 18XX 18XX (I THINK IT WAS 1856 AND 1834 OR SOMETHING)