Ignition circuit diagnosis.

[The Phantom]

Hey, I’ve got my 78 togeather. I even fixed the inop starter gear while I had the primary cover off.
I have no ignition switch locking mechanism, and the kill switch was damaged in the accident. Crossing over plugs, I’ve cranked it over and only get a spark on the right side points. I’m fairly well versed in wiring schematics/ diagnostics but I can’t figure out why the left side has no spark. I’m not sure, but I don’t think the left coil is getting power. I’m no bike mechanic so rectifiers and regulators are Greek to me. Any suggestions would be appreciated.

 

[mike in idaho]

With the switch on and the points open there should be battery voltage at the points arm. No voltage?, power to the coil is interrupted, or the points wire and/or the condenser is shorted to ground.

 

[gggGary]

Crossing over plugs

Not sure what you mean by this?
most points ignition troubleshooting can easily be done with a small light bulb and test leads.
A couple simple ignition only diagrams. Don't forget/ignore condensers.

 

[The Phantom]

Not sure what you mean by this?
most points ignition troubleshooting can easily be done with a small light bulb and test leads.
A couple simple ignition only diagrams. Don't forget/ignore condensers.
View attachment 258150View attachment 258151

Thanks, I’ll get on it this morning. Merry Christmas!

 

[Jan_P]

When I went to the dealer many years ago he always said Point -Point --Point and then check the Point
Can of course be other things .But service there was the advice and I cannot say the Dealer have been wrong yet

 

[The Phantom]

When I went to the dealer many years ago he always said Point -Point --Point and then check the Point
Can of course be other things .But service there was the advice and I cannot say the Dealer have been wrong yet

What? I need a little more explanation. Don’t know what you mean here

 

[The Phantom]

With the switch on and the points open there should be battery voltage at the points arm. No voltage?, power to the coil is interrupted, or the points wire and/or the condenser is shorted to ground.

I believe the condenser is mounted to the upper engine mount. Is that right? There is a ground wire off the condenser, is that grounded to the frame or the rocker cover of the engine?

 

[Jan_P]

What? I need a little more explanation. Don’t know what you mean here

Since we don't know how old or in what status the points are. That is a service item . I doubt any shop are starting look for faults without immediately install 2 x New Points and 2 x New spark Plugs. Not doing anything before that. Nothing
Then timing ignition with gaps .

We dont know how it looks inside under the points cover there can be oil and dirt
Im all for not replacing parts , One can try to clean up and install new insulating washers and whatnot usually leading to new Points 2x within a month or 2.

 

[gggGary]

 

[The Phantom]

Not sure what you mean by this?
most points ignition troubleshooting can easily be done with a small light bulb and test leads.
A couple simple ignition only diagrams. Don't forget/ignore condensers.
View attachment 258150View attachment 258151

The wires coming from the points, one orange one grey? It’s a bit hard to tell. I may have them backwards. I’ve got power to both sets of points. When I crank the engine, no spark. The dwell is set correctly. There are two condensers, I’ve only found one

 

[The Phantom]

Since we don't know how old or in what status the points are. That is a service item . I doubt any shop are starting look for faults without immediately install 2 x New Points and 2 x New spark Plugs. Not doing anything before that. Nothing
Then timing ignition with gaps .

We dont know how it looks inside under the points cover there can be oil and dirt
Im all for not replacing parts , One can try to clean up and install new insulating washers and whatnot usually leading to new Points 2x within a month or 2.

Ok, thanks. The points don’t look like they have fired/ no pitting.

 

[The Phantom]

View attachment 258175

Thanks! How many condensers? 2? I’ve only found one

 

[jpdevol]

Thanks! How many condensers? 2? I’ve only found one

That's Two

 

[mike in idaho]

With the points open, use the end of a screwdriver to short the points spring to ground, see any sparks?

 

[5twins]

For information on points, condensers, and ground wire connections, see my posts #4 and #6 in this recent thread .....

https://www.xs650.com/threads/how-do-condensers-plug-in.65416/

Correct hook-up of the points wires (as the factory intended) will have the gray wire connecting to the upper set of points (for the right cylinder) and the orange wire to the lower set (for the left cylinder) .....

 

[The Phantom]

View attachment 258183
That's Two

Hi, yes there is that one on the to engine mount then there is the bigger one under the frame bar under the tank.

Since we don't know how old or in what status the points are. That is a service item . I doubt any shop are starting look for faults without immediately install 2 x New Points and 2 x New spark Plugs. Not doing anything before that. Nothing
Then timing ignition with gaps .

We dont know how it looks inside under the points cover there can be oil and dirt
Im all for not replacing parts , One can try to clean up and install new insulating washers and whatnot usually leading to new Points 2x within a month or 2.

thanks so much! I took them apart and washed everything with hot water and Dawn. She fired up with little cranking. After 38 years of sitting in a storage container in a junkyard. I so appreciate your willingness to impart your expertise. That was my Christmas present. Merry Christmas

 

[The Phantom]

View attachment 258183
That's Two

Hi, yes there is that one on the to engine mount then there is the bigger one under the frame bar under the tank.

For information on points, condensers, and ground wire connections, see my posts #4 and #6 in this recent thread .....

https://www.xs650.com/threads/how-do-condensers-plug-in.65416/

Correct hook-up of the points wires (as the factory intended) will have the gray wire connecting to the upper set of points (for the right cylinder) and the orange wire to the lower set (for the left cylinder) .....

View attachment 258184

thanks, she is running! It’s a very exciting Christmas Eve here in central Va. She sounds very nice. I don’t see why people re phase these. Sounds awesome. Thank you all so much for your years of experience. Great resource

 

[The Phantom]

View attachment 258183
That's Two

Hi, yes there is that one on the to engine mount then there is the bigger one under the frame bar under the tank.

Ok, thanks. The points don’t look like they have fired/ no pitting.

I had to replace a broken exhaust valve so the top end was disassembled. I cleaned behind the backing plate before it was all put togeather. One more question; there is no locknut on the cam chain adjuster. Is that normal for the 78 year? If not, do you have an extra you might want to part with? I have $

 

[gggGary]

JP's pic is the dual package ignition condenser. The other part is not ignition related, on some years the turn signal flasher is a round can under the gas tank.

See Type D

Ho, ho, ho!

 

[The Phantom]

JP's pic is the dual package ignition condenser. The other part is not ignition related, on some years the turn signal flasher is a round can under the gas tank.

See Type D
View attachment 258227
Ho, ho, ho!

It’s a good thing. She is a 78. So I’m safe. Thanks.
One more thing if you don’t mind. The left side is running a lot hotter than the right side. I can still touch the pipe right out of the head about 3 or 4 min after starting. Any ideas?