I'm new to the forum and have seen things like mine on here, but haven't found a solution. So I'm sorry I'm advance if it's on here and I didn't see it. So when I ride my gs500, it starts fine and runs. But after 15 minutes the right cylinder dies. It has no spark after the ride. But if it sits for a while it comes back. I've replaced the spark plug, the wire and the ignition coil and it still happens. I saw something about maybe the negative wire going bad, or the ICM. How do I test these before throwing more money at them. Thanks in advance.
"the wire" .... which one?
Have you downloaded a wiring diagram? Do you have a multimeter? What year is your bike.
If you have a multimeter you can check for continuity between the ground (negative) wire coming from the ICM (aka CDI). The ICM is the black rubber box on the left side of the battery. The ground wire is black and goes to the negative terminal of the battery.
You want that connection to be solid. Inspect the connections to see if maybe the heat generated from your 15 minute ride is causing the connection to separate.
Have you inspected your signal generator? It is under the round cover on the right hand side of the engine, the cover says Suzuki on it. You can use a multimeter to check the resistance in the sensors. If you have an older bike that has two sensors in the signal generator with a one-tooth-rotor then I heard of a way to test those sensors and the CDI.
If you have the newer style with a single sensor and four teeth on the rotor I don't know off the top what steps to follow to test out those components.
There is another current thread from someone with a similar issue to yours.
http://gstwins.com/gsboard/index.php?topic=69644.60
Quote from: rtalladino on October 15, 2015, 02:04:35 PM
I saw something about maybe the negative wire going bad,
Yep...its the smaller negative lead going to the battery, its the ground for the ignition module, you need to check it and make sure its good and sound.
Also consider the pickup coils, not unheard of them to develop an open circuit as they warm up and clear as they cool. Try playing some heat on them from a hot air gun before checking them.
What is the best way to test the ignition pickups?
Without the factory test equipment.........substitute the suspect one with one that's known to be serviceable.
Not the same problem but I was having no right cylinder at idle but when I revved it came back.
I cleaned carbs again, checked for vacuum leaks, tested coils and then thought it was either the CDI or the signal generator. As I had days before I could find a "good" one to test with I just started checking and cleaning connections. I followed them from the coils backward and everywhere I found a plug I disconnected, cleaned with contact cleaner and toothbrush, let dry and reconnected. Within 20 minutes I had found my dirty connection.
for what it's worth anyway.
I didn't read all the posts but - losing 1 cyl when hot can be crank trigger.
Lucas has trouble shoot one of those in the last few weeks. Find it and try some of those.
Cool.
Buddha.
I just tested the pick up coils today, and when I tested it hot I got no reading from one of them. Then when it cooled it was reading like 500 ohms difference between the two. So I'm really leaning towards that . But I can't find a set of them anywhere to save my life now.
If you are up for fiddling with your bike before you buy new parts for it you can try testing your coils.
Here is how I did it: swap the positions of the pick ups and swap the positions of the wires going into the electrical connector. You will need something to clip off the small plastic tab on the back of each pick up, I used small diagonal cutters. I used a dental pick to bend the small metal tab holding the blade terminal inside the electrical connector.
If you do this and one of the pickups is bad then the dead cylinder should jump to the other side.
If you're just planning on replacing this part then you don't have much to lose by messing with it. Have fun.
PS you might have better luck if you search for "signal generator" I looked on eBay and there are some for sale there.