GS500E Has Power But No Spark - Need Your Thoughts

[tch973]

Accidentally posted this in Projects / Builds, Racing and Tech before I realized this was a more appropriate place.

First off I can't tell you how many posts I've read here but this is my first time actually posting. I'm new to riding and I'm very lucky that a friend has given me a 2002 GS500E to learn on (he just bought a new bike). The problem is the bike doesn't run. Thus, I'm at the beginning of the riding season but can't start my bike. I'm hoping someone with more knowledge than me can steer me in the right direction.

The symptoms are as follows- before it died on him my friend was increasingly having problems starting the bike. One night riding home it died on him and he couldn't get it started; had to have it towed. The diagnosis is that lights turn on, (headlights, dash etc.) but there is no spark.

After reading many posts from here on the subject and armed with a wiring diagram we started working on the bike today. As the old battery was very weak I bought a new one. According to the multimeter this new battery should be more than adequate so that should not be a factor. Following many of the suggestions posted here we checked the following-sidestand relay, sidestand switch, turn signal relay, neutral switch, fuse, turn signal switch. We believe these all to be working though we're by no means adept at wiring.

Interestingly in going through the wiring we did notice that the brake light only illuminates when the rear brake is pressed; nothing happens when the front is pressed.

Firstly, based on the above symptoms does anyone have any educated suggestions on where to focus our efforts? I'm hoping the brake light matter in addition to no having a spark sounds familiar to one of you.

Based on research I know we still have to definitively check the coils, engine starter switch, engine stop switch, clutch relay, and starter relay. For these areas left to test (i.e. engine starter switch) my understanding is to use a multimeter to get an ohm reading and see if it matches what's listed within an acceptable range for that part? Is that correct? If its outside of that range the part has failed?

Thanks for in advance for your input. I can't wait to get this bike on the road and start riding!

[NSRiderGS]

Silly question as I'm sure you have, but there are new spark plugs installed, right? Had some hard starting on mine and stuck a new set of plugs in and so far so good.

[tch973]

Yes sorry should've mentioned-when he was having problems starting up the bike in the fall my friend installed brand new spark plugs.

[TheGreenWeenie]

Have you checked the clutch lever safety switch?

When you say he was having problems starting.. do you mean it would try to turn over but wouldnt? or it would just do absolutely nothing.

Anything specific that makes you think it's wiring and not carbs?

Pull the plugs out and reconnect them to the boot. touch it to the frame or something else metal (don't freaking shock yourself) and try to start the bike. you should see a little spark from each plug.

I suggest testing the plugs because even brand new ones can be pooped right out of the box.

[Fatasianboy]

I just got my Gs back in December in a similar situation. My bike cranked over but didn't start. New plugs, ignition coil, taped off the clutch and kickstand switches. Still didn't spark. Bought a cdi ($40) on eBay, plugged in and started right up! Also check the rectifier($40) when you get it running to make sure it doesn't let out more than 14 Volts. I think that's what fried my original CDI and my new battery. Save yourself the dollars of my mistake!

[xr]

I'm the friend he's talking about. It could be the carbs but before it stopped working I did a thorough re-jetting of the carbs so I don't think that is the issue. I think it's the wiring because we get no spark even when we take it out and ground it (do what you said basically.)
As far as the problems its having as it stopped working:
Basically I would have to maintain the battery over night to get it started. But even when I did that, sometimes it would take a while to get it to started, it would turn a bunch and once I got it going, I would have to choke the hell out of it for a while to heat it up. Although, being an old carbed bike, I assumed some of this is normal. Any time I would take it to class and when I got out, it would be the same issue and if it was a long class some times the bike just would not start and you'd hear the alternator click after it tried to turn over a few times which to me indicated a bad battery issues. I cleaned the carbs and drove it around for a bit more keeping the battery connected any time I'm not on it.

Anyway after it broke down on me once again, I never bothered with it and it sat around forever. When I went back to get it running I couldn't even get a spark and started diagnosing the wiring to see why and here is where we stand.

[TR]

Did this story have a happy end? My bike has no spark too, and it gradually came from bogging on open throttle, then I cleaned carbs which were plugged with gas tank oxide particles, I guess, and installed a fuel filter, checked thoroughly o-rings, floats, and everything, and it started ok, but bogged and died on open throttle, even with just a little throttle. But sometimes started and perhaps due to excesive fuel the engine revved up strong and beautifully for half a minute just to go back yo idle and died again if the thorottle was open. Then noticed orange sparks, and messed up with the coils, even changed signal generator to rule out it, but came to a closed road where there isn't sparks any more.