no spark unless power coil from battery direct.

[ukjules]

I am taking a liberty but if anyone who is electrical
Could look at this thread in other bikes .....
On paper I thought it was the cdi box but
With my pitiful electric analysis I am
Finding otherwise.

(Other bikes thread - no-spark-gpz600r-1985

https://www.thegsresources.com/_forum/showthread.php?250653-no-spark-gpz600r-1985

Status

No spark and solenoid bust.
(the solenoid I bridge to turn over, another coming)

There seems to be an intermittent fault of
Voltage getting to coils.
If I bridge from battery to coil then turn over
By bridging solenoid it sparks.

So why and how do I find why it only works
With direct voltage to coil from battery ?

I put this on here as has interest to us gs
Owners. I am hooeless at electircs have bad colour vision
But have got to this stage ....

[OldVet66]

Look at your kill switch, the power is routed through there to the coils.

[posplayr]

Look at your kill switch, the power is routed through there to the coils.

Yep; that is about it.

[ukjules]

Many thanks for information I'll divert to the other thread in other bikes to report analysis.

I do have a electrics diagram but it is very hard for me to read it.

Thanks what information and I'll post results tomorrow

[chuck hahn]

Kill switches on these GSs are weak. I never use them. Shut off with the key and leave the switch alone is my policy.

[ukjules]

Thanks this thread is slightly involved as it involves another
make of bike but I agree I don't usually ever use the kill switch.

Tomorrow I will get to work on the bike and provide more analysis

[ukjules]

Just to update this thread the issue is now solved and I have updated the thread
in the "others" section.

The no spark issue was caused by mainly a
faulty on / off button. Dismantling the switch and cleaning the contacts with a
dremel worked instantly.
I can also add making new HT leads and cleaning the pickup
connector box were at issue.

[ls428]

You may also consider making "coil relay mod" awhile working on the problem.
The mod added noticeable increase in voltage going into the coils.
It is relatively cheap and easy mod.

[ukjules]

No problem anymore as fixed but I wouldn't mind reading
What this mod entails ?
I reality I have never had an issue with coils or
performance of them.

What does this mod entail ?

[ls428]

See the link below on bikecliff's "coil relay mod", and do search for more info.
On unmodified bike, the power(+12V battery) going to the coils go through ignition switch and kill switch (in series).
Over time, those switches develop wear and additional resistance.
The cleaning the switch contacts will help restoring functionality.
The "coil relay mod" will bypass existing ignition switch and kill switch path (from battery to coil) with a relay.
On my bike, the voltage increase going into the coils was around 0.8V, and resulting in noticeable increase in brightness of the spark.

http://members.dslextreme.com/users/bikecliff/images/coil_relay_mod.html