[rd3500]

that was not fun and I was hoping not to post that soon. fortunately not many cars were around and I pulled safely on a side of the street.

Engine died, electrical problem, all of a sudden. I think I heard a noise like a fuse blowing (impossible at that speed and with the exhaust I have) but if I heard something, it was a similar noise, like a sharp spark or electrical discharge. It might be my imagination too, so I would not consider this too much.

bike is a gpz900, '84. I have been having electrical issue that are familiar to people here. A few days ago the bike would not start, the starter would crank but the engine would not start. I pushed it for a quarter of a mile to a garage and before leaving it there I tried one last time and it started.

I used it during these part few days with no problems, starting right up. Now this. The bike is still outside, I went there and tried this morning and it still does not start. I don't think at this point it will work again by itself like it did a few days ago.

so I was looking at the electrical diagram and I have a couple of questions. First the kickstand switch. It used to work, it has been a couple of weeks that it does not work anymore, or at least the light does not come on. The bike worked even after the light stopped working, I don't know if it matters but it is in the electrical diagram.

second if you can please tell me on the lockout switch, what current should I get from what wires. That's easy to check and I had problems with that switch before, meaning that I was not getting the right current (although the engine was working anyway).

finally, I opened the junction box that was full of that green stuff copper does for corrosion. I cleaned it, put it back together and it was working for a while. I don't know if that makes any difference.

from a previous post bountyhunter suggested to check the ignition switch, kill switch and connectors going to the coil. I will try to figure out from the schematic how to do that. any other ideas so I will go to the bike tomorrow with my tools and see what I can do.

last, I checked all the fuses and they all look fine. Bike is parked now at a gas station, poor girl.

thanks a lot in advance,

Walter

PS: diagram attached View attachment 15172

 

[BR549]

When you turn the key to the "on" position now, does anything happen? Do you get power anywhere? If so, then where? If you're getting power somewhere, then does the starter work at all? Did you check all the fuses after this latest incident?

 

[A2rider]

I commend you for wanting to work on it yourself. If you have the time or money, find out who in your area works on older bikes, and have them take a look at it. Chasing electrical gremlins is biotch.

 

[rd3500]

A2, I will do what I can then go to a mechainc, it is also that I want to know how it all works, I have always been curious about it.

BR, when I turn the ignition, the neutral and oil light come on. The kickstand light does not even if the kickstand is there. That problem started happening a couple of weeks ago and the bike run fine even if that light did not come on with the kickstand open.

I checked the fuses after the incident and they were all fine. The starter works but the engine does not start. I have to say that the starter works because I put a extra switch connected directly to the starter relay (there is another thread about that all issue). I could not get the starter button on the handlebar to work, so I had bypass the entire starter circuit. Bike run fine for several days even if I did that.

I don't know if something gave up at this point, I can check it if I know how.

 

[gpz600oz]

i dont know if this will help but have a look any way

i know a capacator will make a farly good pop when it decides to give out but i cant think of where they would use one on that model bike.

the green stuff(corosion) in your fhuse box can be caused by a low valtage leak. things like live wires that are not insalated properly or moisture shorting across.

i would simply by pass the kick satnd switch to eliminate that as being a problem just by pluging the the two wired that go to the switch on to each other.

i read you bypassed the starter circut and still had it working so i guess that means your arnt using the starter circut relay in the junction box? if your still running your starter though the junction box it may be worth opening it up to see what sort of condition its like in the inside. there is a electrical board and two relays inside maybe one of the circuts has coroided though or there might be damage to one of the relays. I have testing instructions for the junction box on my 85 gpz they are proberaly the same i can post them if you need.

but first check all basics like fuses. bad earths, and shorting wires check your coils, spark plug lead ohm readings etc.

 

[rd3500]

thanks gpz600,

I am pretty sure you are correct and there are no capacitors. About what I heard, I am not really sure about it and I was going relatively fast so there was a lot of sound. It was probably more my impression than anything.

I will unplug the kickstand switch. I don't think the bike should not run if the kickstand is open but I will anyway, one less thing to worry about.

About the starter circuit, I went through it before on another thread. the manual shows 3 relays in the box, I know most of the time (and as you report) there are only two. I am talking about the round ones, excluding the turn signal one (which is missing in my case anyway).

So I have two relays and I don't know what they are. Actually, one is the main relay for sure, don't know if the other one is the starter circuit relay of the headlight relay. They are both present in the manual but I only have one. I know sometimes is written on the junction cover but that's not the case with mine. I bypassed it anyway because the switch I installed just gives 12V to the starter relay and that makes the starter work.

The main realy is working because I get the neutral and oil light when I turn the ignition switch.

About the junction box, I opened it and even opened the tracks and cleaned it inside. there could be something wrong with that, although the bike was working for a while after I reinstalled it. After I was done installing the switch to make the bike start, I noticed the corrosion, cleaned the box, reinstalled it, and the bike was working. I went around that day, stopped and started a few times and then it would not start again. Waited 30 mins or so and it started back up.

I then used it for a couple of days with no problems, and now it stopped and when I tried this morning it still did not start. That's where we are.

 

[BR549]

thanks gpz600,

I am pretty sure you are correct and there are no capacitors. About what I heard, I am not really sure about it and I was going relatively fast so there was a lot of sound. It was probably more my impression than anything.

I will unplug the kickstand switch. I don't think the bike should not run if the kickstand is open but I will anyway, one less thing to worry about.

About the starter circuit, I went through it before on another thread. the manual shows 3 relays in the box, I know most of the time (and as you report) there are only two. I am talking about the round ones, excluding the turn signal one (which is missing in my case anyway).

So I have two relays and I don't know what they are. Actually, one is the main relay for sure, don't know if the other one is the starter circuit relay of the headlight relay. They are both present in the manual but I only have one. I know sometimes is written on the junction cover but that's not the case with mine. I bypassed it anyway because the switch I installed just gives 12V to the starter relay and that makes the starter work.

The main realy is working because I get the neutral and oil light when I turn the ignition switch.

About the junction box, I opened it and even opened the tracks and cleaned it inside. there could be something wrong with that, although the bike was working for a while after I reinstalled it. After I was done installing the switch to make the bike start, I noticed the corrosion, cleaned the box, reinstalled it, and the bike was working. I went around that day, stopped and started a few times and then it would not start again. Waited 30 mins or so and it started back up.

I then used it for a couple of days with no problems, and now it stopped and when I tried this morning it still did not start. That's where we are.

If your starter is working, then I doubt the problem is in your starter circuit. I also don't think the problem is related to your kickstand switch. My '85 will start with the stand down and I have completely O.E.M. wiring. It will even keep running in gear with the stand down after you release the clutch lever.....something a modern sportbike won't do. Your kickstand warning bulb is probably burned out.....like mine. Your bike won't start unless it's in neutral and the clutch lever is released, however.

Have you checked the condition of your IC igniter? It doesn't smell burnt, does it?

 

[rd3500]

I have not checked the IC igniter, the bike is currently parked in a gas station, I am trying to get it back home, probably tomorrow. I took the juction box out, I will open that again now given that it was the last thing I touched before having the problem. I hope I will find something there.

 

[BR549]

I have not checked the IC igniter, the bike is currently parked in a gas station, I am trying to get it back home, probably tomorrow. I took the juction box out, I will open that again now given that it was the last thing I touched before having the problem. I hope I will find something there.

Just be patient. It might take a while, but you'll get it figured out. Let us know what you find.

 

[rd3500]

well, here is an update. I went back to the bike today and tried to make it start after cleaning up the junction box (did not find anything wrong with it). Of course it did not start.

Here is the weird part though. I towed the bike back home and I took the front light out to attach the cord to tow the bike. Near my house I let the cord go, put the bike in second gear and it started.

Now, unfortunately I did not try to start it soon after I took the headlight out, now I am wondering if that could make a difference. Because now that I remember, I had the problem after I put the light back on. When it stopped last time I was testing the bike after installing the front light back on the bike.

Could there be something in connection with the front light that can create this problem? This is driving me crazy!

 

[StarGate]

I doubt the problem is with the headlight but the headlight could be applying pressure to damaged wires or lose/dirty connectors that is making them lose connection.

 

[OKC_Kent]

I'll toss in my .02 cents with Stargate, I think the problems all relate to old, dirty corroded or loose connections. Spend some quality time in that harness with some contact cleaner, steel wool and di-electric grease. It will be time well spent.
Hit all those connectors good. Pop open the plastic connectors that have 6-8 wires. The wires can be released from the plastic block with a pin. Go through all the switches in the handlebar controls too. I even had to unwrap the wiring harness on my bike to replace bad wires. It's not hard if you do one at a time, but it is time consuming. Some guys even advocate getting rid of the bullet connections and soldering everything, but that's a bit much for me.

 

[Kawa 1982]

Here is another $0.02 worth.

Somehow Kawasaki managed to stuff a zillion wires and connectors into the headlight bucket. One of those connectors connects the main leads from the ignition switch to the wiring harness. In my case that connector has six wires and the plastic connector is white. I took apart every connector I could find including the ignition switch and cleaned them with contact cleaner and put a good amount of dielectric grease on all of the connectors prior to reassembly. Be careful when you open the wiring on the bottom of the ignition switch because there are one or two little balls that want to get lost. You may discover that the problem with your side stand switch is in the headlight bucket too. Maybe the connection came loose when you were in there before.

 

[rd3500]

thanks for the answers guys, I will do what's suggested. I already put contact cleaner on every connector I could find about a month ago. I need to clean the ignition switch and I am thinking about changing all the wires.

I can find the entire wire system from a working bike so I am thinking about replacing the all thing and the junction box. Hopefully that will take care of it. I was happy the bike started again yesterday, so nothing is burned fortunately.

 

[Alizard]

I have not checked the IC igniter,

That is the most likely failure. All modern ignitions use some kind of electronic sensor and electronic ignition (like CDI). They can and do fail. Also, the sensors that sends the signal to the unit from the crankshaft also fail.

 

[Alizard]

thanks for the answers guys, I will do what's suggested. I already put contact cleaner on every connector I could find about a month ago. I need to clean the ignition switch and I am thinking about changing all the wires.

I can find the entire wire system from a working bike so I am thinking about replacing the all thing and the junction box. Hopefully that will take care of it. I was happy the bike started again yesterday, so nothing is burned fortunately.

That's good, but you still have an intermittent that makes your bike go dead at random times. It might be a wire or connector in the harness. I had the same problem with my CDI (random times the bike would not start). I finally repalced the connector at the unit and wires into the harness and that fixed it. YMMV

 

[V2K_CCTX]

Make sure every ground is good. My problem was traced back to a faulty ground!

 

[spectrerider]

pull all fuses and wire brush clean (dremel) the fuse holders. carbon builds up between the fuse and holders preventing reliable electrical contact. check to see if fuse holders hold the fuses tight. heat and vibration, stress fuse holders and allow a thin film of carbon build up between fuse and their holders.

 

[rd3500]

thanks, I will do that. I already cleaned the fuse holders with contact cleaner, now I am about to change the junction box, I will make sure I will clean the new one.

 

[rd3500]

I was talking with my cousin just a few minutes ago. He owned a gpz900 a few years ago. He was telling me that his bike for a while used to stop for no reason and after a while it would start again after he did nothing to it.

It was a nightmare until somebody realized that the problem was the tank cap that was not "breathing" properly. I don't know how to say it, but the little hole that is suppose to let the air out was clogged, so the bike would stop, I guess because the gas would not reach the carburators. After cleaning that up, the problem stopped.

I have been having the same problem (at least I hope) with the bike stopping for no reason and then starting again after a while (and after I have done nothing to it really). That would be nice, an easy fix and not electrical related.

I will check it tomorrow and report back, in the meantime I wanted to mention it in case somebody has the same issue. It is easy to check.