85 X dying.

Last fall during my last ride my XJ700 died when at speed on the highway, just shut off and would not restart. After pushing it for about a mile and trying it several times I hit the button and it fired immediately like there was no problem. I rode it the last 3 miles with no issue. It runs great when it runs, no missing or issues.

Problem is now I have fired it up for the season I'm real concerned about heading out and having this reoccur. Before I do I want to be prepared and bring a meter and some ideas along...

I'm thinking for sure electrical, and not coils or pickups because that would surely run on 2 cyls. Not thinking fuel or it would sputter when it died and/or run bad when it restarted.

Ideas would be helpful. I wiggled all the connections I could get to when it died including ignition switch, kill switch, etc.. I'm wondering how do I jump out the stand relay and neutral sensor to take that out of the mix?

I live 30 miles from town with nothing in between so when it dies out there it sucks...

 

tci i would suspect when they get hot they fail when they cool down bike will re start and run fine. If you are sure its not vapor locking i would suspect that

 

Vapor locking as in tank vent? No, that's not it as the first thing I did was open the cap to check to make sure I was not stupid and ran it out of fuel... I have a clear section of line between the tank and the carbs and it was full. Also it went dead like ignition, not ran out of fuel.

 

TCI would be HIGH on my list to check.

 

I don't think the TCI would be overheating, per se, but rather a bad component connection and/or the capacitors failing. Had the same thing happen with my 750. Pulled it out and opened it up; replaced all the caps and touched up all the solder joints I could get to. Hasn't happened since.

 

A capacitor failing or solder joint means what THE TCI IS GOING BAD. Not saying it cant be fixed but most people wouldn't have a clue how to fix it and its easier to replace with a used one rather then pulling apart and soldering and replacing components

 

where is the TCI and how can you check if its good or not?

 

I can surely fix the TCI at the component level but was hoping that I had a simpler problem like the stand relay or kill switch rocker. It is what it is though.... I know my coils are not good and am going to go to the Accel kit when I have a couple of hundred dollars to put into it. Maybe the bad coils stressed the TCI transistors?

 

Has the fuse box been examined thoroughly?

 

Hmm, never checked the fuse box because it restarted. Probably should have gone there first but fuses don't generally un-blow so I didn't really think about it. I'll check this for corrosion and damage today.

 

Fuses don't un-blow, but loose/corroded/brittle wiring can re-touch. Does the bike still have the original fusebox?

 

Sort of. Electrolytic capacitors have a limited operational life. They can fail, burst, and stop working even when everything else is functioning properly. Solder joints on production-run assemblies (of that era) are rarely perfect, and solder joints are effected by heat cycling. They can gradually pull away from the PCB traces. Transistors are a bit hardier, and while they can fail, it's less likely that they will. In short; if your TCI is failing (or has failed) they can be repaired. Any TV repair shop can do the job (TV repair shops do still exist. Even the tiny bassackwards town I live in has one). Anyone with a HS level of electronics training can do the repair as well.

Having said that....I do keep a know good spare on hand so I don't have much downtime should the TCI on my Seca fail.

 

The fuse box on the X is behind the "dash" and is ATC blade fuses. I just pulled the front off and it is pretty darn clean. I did replace the ignition fuse and clean the socket with electrical cleaner, wiggled the new fuse to get a bright shiny contact surface and can't see where there is any issues here. The old fuse was slightly oxidized on everything but the contact points (not corroded) now it's perfect. Can't see as this was a problem that would kill the bike. Maybe there is a problem on the back side....