1984 XS650 Special NO SPARK

dubepj

XS650 Enthusiast
Messages
57
Reaction score
18
Points
8
Location
st. albert, alberta
just got the bike home. 1984 XS650 Special. took plugs out and have no spark when grounded to heads. Some ignitions need plugs in the hole so there is compression. Should I have spark when grounded but no plugs in the holes???
If there should be spark and i don't have any where would you guys begin to look??
Thanks.
 
Yes, you should have spark by just grounding them. If it's the stock TCI ignition, both plugs need to be grounded to get a spark and to prevent damaging the coil. So... we'll need to know more about your bike. How's the battery, which ignition is it using... anything relevant.
 
There Should be spark
Fuse
Ground
Battery +12 V or more
kill switch
 
You don't need to pull both the plugs to check for spark. Just pull one and ground it to the head. Leave the other in and connected.
 
If you can't see spark with a fully charged battery, you need to start checking things. At the coil and TCI box you should have full battery voltage on the red/white wires. A .1 or .2 less is ok but much more needs further checking. These voltage drops can be in any connection between the battery positive through all the igniton system, and ground back to the battery.
A muli-meter is your friend.
Leo
 
Thanks for replies so far guys. Battery is fully charged and checked by professional who put a load on it . It is good he says. Checked primary and secondary windings in coil and are within parameters. Now I believe the Ingnitor unit (CDI box)is NFG. Any way to check this unit. It's the one with 8 pins. (Actually only 7 one blank),

Thanks.
 
Any way to check this unit.

I don't believe there is ..( Unless being an Electronics guru ) The fault finding procedure is check everything else and then if that don't help replace the TCI
It was up here on the forum not long ago .
And is uploaded . I am not at that computer now to find it but if I recall right I took it out of a Manual there

https://thexscafedotcom.wordpress.com/2011/01/10/xs650-manuals/
 
Ok Checked every thing and all is good so now looking for a TCI Box
I'll go to local used parts guys and if cant find a used one what do you guys recommend. Back to points or buy after market electronic setup. Which one do you recommend.
 
If you can slog your way through this thread.... it's a $20 replacement for the TCI box. Not quiet plug-n-play.... but close.
 
Boyer Bransden is an Option
It has made ignitions for British twins for ages
I have used two different on two different bikes
As long as the charging i controlled it is a solution -- as good as any --- perhaps better than many. other
Plug and Play more or less
Points has the problem with the advance unit that is causing problems.
 
Ok good Ideas. Fuse is good. Battery is low On slow charge now. I'll check kill switch tomorrow.
The electronic ignition system needs pretty much full battery voltage to function reliably, so your battery has to have proper water level in all cells and be in good usable shape before you check anything else. There can be many different reasons for your issue, but a good place to start is to separate and clean all the electrical connectors, following a good colored wiring diagram. If your bike still has the original fuse block with glass tube fuses, the spring clips that hold the fuses can lose tension over time and crack, degrading voltage and current flow. Ensure that the ground cable from battery to frame under the seat has clean, tight connections at both ends. Check the length of the brushes in the generator; they are "wear" items. The "outside" one may be shorter than the "inside" one, which is normal on used brushes, but both must exceed the minimum length indicated by a line on them. Clean the rings on the face of the rotor that the brushes contact. Doing these steps first ensures that proper voltage will be available to the rotor, stator, coil, lights, etc. Check the condition of your coil, plug wires and boots; replace as needed. Then follow the steps in the charging guide if a known good battery does not charge up.
 
Ok good Ideas. Fuse is good. Battery is low On slow charge now. I'll check kill switch tomorrow.

Hi dubepj,
check stuff while your bike battery is jumpered from a big ol' car battery and see If the problems go away.
 
Morning everyone.
Will a TCI box number 4M4 from earlier bike work for my 1984 SK model?
Mine was labelled 5V4.
Some of those can be found more easily.
Also I did try boosting form a car battery.
Maybe my magnet on. the rotor is weak. It is magnetic but not very strong.
 
Also guys did a compression test. Cold since bike is not running. Got 100 PSI on Left and about 90 right. Added some oil and results did not change much. Is that real low??
 
As a cold test, no, that's probably not too bad.

The only difference in the boxes that I'm aware of is an extra wire on yours for the sidestand safety relay. You don't need that and it's actually best to get rid of it anyway, so the early box should work fine. You may need to change the plug is all so it matches up to your harness (6 slot to 8 slot).
 
Morning again.
Thinking seriously about changing my 1984 Model SK back to points. Doingf some reading and someone says I have to change the charging system as well for this to work, I hope not true because i can get parts from XS direct.com for about 240.00. Why do I need to change the charging system??
 
Why do I need to change the charging system??
You don't. It's the same one the points bike uses. One's A type regulated and the other's B type regulated.... neither of which has any bearing on what iggy system you use.
 
thanks Jim. Has anyone gone back to points. Can this be done?? Only issue I can see is the newer models did not have bushings in the cam shaft.
 
I know it's been done. Maybe someone who's done it will chime in.
 
Back
Top