79 XS1100 SF "No Spark"

[bks11s]

A 1979 XS1100 SF has just come into my possession and it has supposedly ran fine until now.

It doesn't start and after a little more analysis, it doesn't appear to have any spark at any plug. We tested for power at the red wire to each coil and they both have power. I have read a lot of threads on coil testing and have since tested each coil and each read 2.2 ohms at the primary leads and 1 at the plug wires.

Does this mean that the plug wires are bad or the coils or neither? It seems hard to beleive that both coils or all four plug wires would have went bad at the same time.

Any suggestions on what to check or do next.

Thanks,

[DiverRay]

Welcome to the site!!
Go to the main forum page, and check the "tech tips". We have been through this a number of times, and you should be able to get all the information you need from that section.

[Ken Talbot]

Re: 79 XS1100 SF "No Spark"

Originally posted by bks11s
It seems hard to beleive that both coils or all four plug wires would have went bad at the same time.

Yup, but real easy to believe that two pick-up coil wires could be gone. That would shut down the spark.

[bks11s]

Thanks a bunch for the responses, I will check the coil pick-up wires tonight.

[TopCatGr58]

Hey Bks11s,

Did you measure the spark plug leads with the caps on or off?

The caps have resistors inside, and can also corrode, not to mention the place where the caps screw onto the wire ends! Remove the caps and IF any corrosion, cut 1/4" off the ends and then retest/measure! IF you are only getting 1 ohm, then it sounds like the coils have shorted internally!
T.C.