no spark?

[carlray]

I hope that you all can help. I have had little experience tracing electrical problems so I trust the more experienced out there might be able to lend their minds and experience and guide me through this.
yesterday on a ride on my '78 900 GTS I experienced a loss of spark; it just died. I saw the ground light just flicker once, incredibly brief and then remain on, but the engine died there after. Maybe this might help in diagnosing but maybe not?

All electric works including my lights, dash lights, turn single etc.. but I am not getting any spark to the spark plugs. I took out the plugs and grounded them but had no spark. the bike turns over - electric starter ok.

so this is where I am. I know that I work backwards in concept but i have no experience as to where to go next or what to look for -coils - ignition ...how do you diagnose? how would I begin to research this problem?

thanks for any help, I just want to get a few more days in before the weather changes if this is an easy fix......i hope.

thanks in advance.
CR

[BevHevSteve]

Carlray - nuthin is EZ.... but........

pull the left sidecover, check out those wires. Bet they are mush right? OK now time to replace them, from the pickups to the transducers. Take good notes on what goes where, and find some GOOD wire that is teflon coated for high temp etc........

[carlray]

thanks Steve,
I did read something that talked about this but it seemed to be only Bosch related, if I am understanding this correctly. I have a ducati ignition so i did not think that this applied. in any case this is somewhat hopeful and I will get into it in the next few days. I will also go over that post as well for any details that might be helpful.
another somewhat related question, do you still carry the ignition kits for this 900 gts? I thought that eventually I would replace mine if I ran into any problems. It had exhibited some ignition problems this summer and I had it checked out to confirm that there were some issues, it was missing around 3200 to 3400 rpm so I thought that I would wait until this coming spring to make the decision to replace the ignition. I am not sure if this current problem might be linked but i'll have to see once I get into it and maybe this might solve two problems.....it would be nice but I will not hope for too much, just want to get it running again

I'll post all my info and document it well.
thanks
Carl Ray

[carlray]

Steve,
I wanted to update you all on the progress.

I first took off the tank so I could get a clear look at the transducers and other electrical components. I also found out that I might check the ignition stop relay. I wanted to do tis first before I got into any thing.

So after testing the transducers I found that there was in fact spark from the front cylinder and that both transducers were operational. however, there was still no spark from the rear cylinder when kicking it over or using the electric start. After this diagnosis, I surmised that I must have only checked the rear cylinder when I sent in the last post.

So this was hopeful. at this point I recalled something that the Ducati mechanics that checked out the bike this summer had mentioned. At low rpm the rear cylinder was weak and would not fire regularly, but at a point over 1000 rpm it would.

I thought that I would try to start the bike as at this point it seemed as it had been this summer. it did start, this was a good point of the day, and I checked while running if the rear cylinder had any spark at all, as the guys told me that when at idle it was sporadic at best if not firing at all, but if I applied the throttle then if would begin to fire as it should. I did this only a few times as i am sure, or not, that it might not be acceptable to run the engine like this; at least it is clearer now.

So this is where I am. I read the posts about the Bosch set up, I believe that my ignition is different, Ducati as I had mentioned before, but I will get into it in the next few weeks when I have some time.

Could anyone out there let me know what you think. I would like to fix it the right way, if I need to get an ignition module please let me know if you have any experience with this and about the compatibility of the DMC with an electric start bike and if there are any mods that i would have to perform. I have heard with the SILENT HEKTIK you have to mill out some space or modify it in order to get all of that associated mechanisms to fit properly with the electric start. this may be an older model than they produce now, as I just saw one for electric start bikes, and I will check this out in the next few days. i would rather just bolt it on and not even know that it is there other than smooth riding.

I am just learning about this so i am sure i have made some mistakes in terminology and please feel free to advise. I really would appreciate it.


in any case, any help would be much appreciated.


thanks to all in advance,
CR