Help please

My 1980 xj650 is frustrating the hell out of me ,bike runs great when it goes but intermittently stops and has no spark ,i bypassed the kill switch ,got on it today & it fired straight up ,rode 100 yrds and it just stopped no spark ,so how do i trace the wiring ,with ignition on there is power both sides of fuses ,where does the wire from the ignition fuse go to ,i really think it is a connection fault or partially broken wire as the bike goes really well when it runs ,help please

 

Hi Mick, first if you still have the original fuse box change it out for a blade type, next pull each connector block, shoot some electric contact cleaner in both sides & push them back together with a dab of dielectric grease (keeps the air / moisture out), see how that goes.

 

thanks wizard ,have already fitted a new blade fuseblock ,but will do the connections with grease ,spoke to a mate tonight & he reckons its the ignition switch ,apparently when they get worn they play up or the solder on the back fails ,so ill check that out too ,something silly ,not game to ride it too far ,too heavy to push

 

Does that bike have a kickstand relay? If it does, I would remove it, don't jump anything, just remove it and see if it still dies. On my Seca it's the forward most gold colored square relay near the coils and it has a small dot of yellow paint near the connector. It grounds the ignition system if it doesn't have power or is failing. There are other things that can cause the problem also, but that's an easy thing to try if it has one.

Mike

 

If that is the problem, you will want to replace the spring on the kick stand. I have heard about this problem on other bikes. The spring gets weak, and you hit a bump, and the stand drops just enough to trip the switch. You will want to grease up the mount, and make sure there is no gunk near that could be keeping it from going all the way up.

 

the bike doesnt have a relay ,greased all the plugs with dialetic grease ,bike will run & then stop intermittently ,has 12 v to red wire on tci,when running can go up to 14v ,when it stops if i leave it for a while it will start & run again ,i am suspecting something inside the tci like a resistor ,any clues from anyone

 

I had a problem like this on my Sportster. It was a wire in the headlight that wore to the point where it would short out the electrical system. Check all the connections and wires. Look for loose connectors and areas in the harness that rub, especially around the neck. That may be the problem.

It could be also the box, like you stated. We had an old Ford pickup that would act the way you are describing. You would be driving it, and then nothing. Wait until the engine cooled and it would run fine. This would happen every week or so. Talked to the Ford dealer, it was a common problem with that model ignition box. Replaced it, and never had a problem with it again.

Electrical problems can be a pain in the...

 

Yeah its very annoying ,dont think any wires are shorting cause even when there is no spark it still has power to tci unit & i would have thought that if wires shorted the ignition fuse would blow ,i really think its probably the tci but havent got a known good one to try

 

Had an MG that would do it. A little cool water an the ignition would bring it back to life. Replaced with an electronic module and also never had a problem again.

 

Actually, it's not the Spring ... it's the Actuating Rod that goes through the Hole drilled at the top of the Side-stand.

The Hole isn't Bushed and the Rod is close to the same diameter.
It doesn't take much grime to render the Rod getting stuck.
Although it's Spring Loaded ... the Spring is weak and the Rod can hang-up.

If the Bike continues to behave as you say. Open the Headlight Bucket, unplug the Ignition Switch and test the Ignition Switch for getting old and funky.

The best thing to do for your own peace of mind is to get the Ignition Trouble-shooting Flow Chart and check-off each element.

 

Also why dont you check the Ground wire if its intact (black one)My xj700 has right below the tank near the coils..unscrew..clean with sand paper apply some dielec grease and tighten them again..i have had trouble with them...doesnt hurt..but could be the culprit. Good luck !!

 

hi ,reading through the forums i found where chacal said you may have a problem if you used a tci with 4 pins in a 5 pin harness ,what about if i use a xj 750 tci with 5 pins in a 1980 xj650 with 4 pins ,maybe this is why im getting intermittent spark or would it just not run at all ,it was the only tci i could get ,any thoughts

 

Sorry to come in to the conversation so late, but here is my thought. If the TCI was the incorrect one, (4 vs 5 wire) it would likely not run at all.

Does the bike shut down while idling or only when you are riding? If it shuts down only when you ride, it might be a wiring issue, but not necessarily. It could be in the TCI. If it quits while idling too, it is probably a transistor or other component in the TCI breaking down when hot (transistors are known to do this.) It could also be a faulty solder joint on the TCI board. The TCI has inputs and outputs. There is a 12 volt input and then inputs from the pick-ups. When the bike quits check these and then check the outputs to the coils. If the inputs are correct and there are no outputs, its probably in the TCI.

 

I'd disagree. The difference between 4-pin and 5-pin (besides timing curves), is the extra pin which is used to disable the ignition based on the side-stand safety circuit. A 5-pin TCI should run on a 4-pin harness.

Thing is, the TCI defeat is actuated by pulling the extra pin to ground. Mick, what is the extra pin connected to now?

 

the extra pin is not connected to anything & the bike does run & run well,just intermittent spark which i believe to be a fault in the tci ,i am just trying to locate another one so i can see if that fixes the problem & i will get a spare to put under the seat

 

You might try a "pull-up" resistor on the "extra" pin. Say 1K Ohm between that pin and the R/W wire. This would be to ensure that the disable pin doesn't think it's being grounded due to noise or something.

 

yeah ,bit out of my league ,electronics ,i have another tci on its way ,so ill try that thanks

 

A quick FYI, 4 and 5 pin TCI units are swappable. I just ran both on my 750 Seca (which uses the 5 pin). Both work just fine. Other than a different advance curve (and only slightly), they are the same internally (save the output SQL mentioned).
I do offer a refresh service for TCIs that have a removable cover. I cannot, as of yet, work on the sealed units but am working on it.
I would highly recommend you open up your unit and verify you don't have any cracked solder joints.
Best of luck Mick!

 

put another tci unit on bike & it seems fine have ridden it a bit now,few other things to sort but electrical gremlins seem gone Thanks for everyones help