81 XJ550RH Seca Spark Issues

Hello,

Needing some help getting my Seca back onto the road. I did a pretty big overhaul of the bike this winter but was pleased to hear it run before moving out of my apartment after graduation. I went to start her back up after moving and being trailered and she would crank but not turn over. Shot with ether for some motivation but nothing. Pulled cylinder 1 plug and found I had no spark, checked the rest of the cylinders and found the same story.

I took a break from figuring it all out since I had to get my other bike put together but now I am back on focus. I checked the obvious after a 2 hour trailer ride but all of the grounds were still in place and tight. I then went to my Clymers and looked for any troubleshooting tips. Did all of the tests for the ignition system, everything tested and was within spec. Battery/coils/plug wires are in good condition/pickup coil/stator/etc. were all in good shape and were within spec. I was able to secure pretty much an entire electrical system off of a known running 82 XJ550RJ and started with switching out the TCI box. Nothing. Then switched out the starter relay for the same result. I had done valve stem seals this winter so I checked my work again with the cams to make sure all of the timing marks lined up, timing isn't adjustable but wanted to make sure it was all in the right spot and it was. I would think though even if I wasn't lined up perfectly I would still get something.

I tested directly at the coils and found they are getting 12v at the positive terminal and then when I hit the starter it drops to about 6v with intermittent ground. I tested with a set of Dyna coils I'm planning to put on the bike and they produced no spark either.

I've gone through and checked the entire electrical system and it is all looped and grounded. I thought about it and was worried that there may be an issue with not having the headlight/turn signals/horn/etc. connected but the initial incident happened with everything connected besides signals or a horn. The bike also ran in that state which puzzles me.

I'm pretty much to my wits end with this project and I don't know what my next steps would be. I've done a couple of things to the bike in regards to the electrical system with deleting the side stand switch for track days and clutch switch for a new lever. For both of these I just tied the wires together securely with a crimp connection and wrapped with some tape. If these were an issue though the bike wouldn't crank so I have a hard time believing they're the culprit. I've done many hours of reading here, on other forums, CV's wrote on how to build custom harnesses, etc. and nothing is coming to mind. My Dad went over everything as well and we both couldn't find anything that would cause this issue. I'm hoping someone here is familiar with this issue and hoping that it is something simple/stupid.

Cheers

 

Sounds like a TCI related problem.
Had similar problems regarding 12V to 6V and it turned out to be the TCI, after troubles with the sparkplugcap resistors.
You can read more about this in the SecaRattopic.

 

Could you link that topic please? I can't find it here.

I have replaced a bad cap with a new NGK cap and still no spark there along with a different TCI unit from a running bike.

 

do a voltage drop test on your battery.
if voltage drops to 10 volts or less when cranking bike will not fire tci even though it spins fast.

with all components in spec battery may be issue also if you used starter fluid , to many times it may have fouled the plugs

 

I'm sorry, wishfull thinking on my part, there is no SecaRattopic .. yet..
In the topic Plugcaps is something I wrote about this.

https://www.xjbikes.com/forums/threads/plug-caps.129201/#post-652131

 

remove your sidestand relay up under the seat this is a better bypass of the sidestand switch than cutting and crimping wires

 

I’ll do that text when I get back to the garage. I noticed my alternator brushes were right at the replacement mark, would this affect spark? I checked the plugs and they had a little carbon but were fine. Tested with a fresh plug too but no difference.

 

the alternator has no real output until bike is running.
when running you will be able to measueer voltage at battery at 2k rpm and higher it should be 14.8 volts max.
you should plan on changing the brushes soon

sitting voltage of battery should be 12.8 volts so that will be the first voltage to record then the drop voltage

 

Was able to find some time to get back into the garage and focus on the Seca. Did a voltage test on the battery and these were the results.

Ign. Off: 12.8v
Ign. On: 12.5v but continued to drop until 12.15v
Cranking Over: 10.4-10.45v
After Cranking: 12.25-12.3v

Above results were unplugged from the wall. Tried to attach the jump pack, jump pack wouldn't sync up to jump which concerns me about the cranking volts to the Seca battery. Had the battery attached to the battery tender that was plugged into the wall and made sure the battery was full charged, no change. I took the battery out of my SV650s and plugged it into the system, still no spark. I rode the SV today so I know the battery is good.

Puzzled is one way to describe it. I have no clue where to go next but I'm going to order a new battery since the current one is 2 years old and was $12 to begin with. Along with that I'm going to get new plug wires and caps with resistors and hook them up to the new Dynatek coils. From there, I have no idea where to go.

 

Bump, pulling back out for this winter and trying to come at it with fresh ideas.