1979 RD400 Daytona Special Ignition Questions

[KANDY]

Hi All,

Happy New Year

I am in the process of Building RD400 Daytona Special Canadian Bike. It has CDI Ignition.

All the wiring done all the lights works as it should, No Spark. Found out coil is defective - Secondary resistance is infinite

Could you guys guide me how diagnose to make sure Stator and other related parts are in working order.

While I am waiting on the Ignition Coil(going to use RZ350 Coil), could I be able to test by using 1977 RD400 coil.

Please help out.

Thanks to all

[rodneya]

A coil from a points bike will not work with the CDI ignition.
Im pretty sure the RD350LC stator was the same as the daytona, so you may find more testing info on one of those

Found the LC specs

[KANDY]

Thanks rodney,
Will update after testing.

[m in sc]

hook up a meter to the wire that goes to the coil, and kick it over, should see a spike of ac voltage.

[1976RD400C]

Here are the resistance values
Ignition coil   primary .33 ohms     secondary  3.5K
Source coil that charges CDI   red to brown 5.3   brown to green  225
Pick up coil  115
Charging stator coils   .4

[KANDY]

This is what I got
Red to Brown = 5.1   
Brown to Green  249
Pick up coil  84
Charging stater coils   .7

Hope this will work.
Waiting for YFZ350 Coil
https://www.ebay.ca/itm/254835446461

[rodneya]

Those cheap Banshee coils can be a headache. A lot of people dont trust them. OEM, Dyna or Nology are the only ones that work reliably and consistently.

[KANDY]

hook up a meter to the wire that goes to the coil, and kick it over, should see a spike of ac voltage.

I connected the meter on the Orange and Black wires that go to the coil, there was a spike in AC (something like 76, 97,106 while I kick)
But still no spark. Does this spike mean Alternator, Regulator Rectifier and CDI are good.
Please help out.

[m in sc]

if it were me id try another coil. initial assumption is that yes, the rest seems good. also worth doing the same at the ign pickup wire, it should throw a slight voltage spike when kicked over.

[rodneya]

How are you checking spark? Are both leads grounded. If only 1 lead is grounded it will not spark

[m in sc]

yup. BOTH plugs need to be touching ground for them to spark. If one is just 'open' the other one wont spark either. rodneya is correct

[KANDY]

Thanks,
Need to look at the wiring. Flasher is giving trouble.

Both plus were Ground while testing. I will get back to you.

The coil i was using was brand new, the one from the link provided above.

[KANDY]

Renewed all wiring. All lighting works good. But no spark.
I must have checked wrong, There is no spike of AC on Orange and Black Wire going to the Coil primary, when I kick over. But I could see AC spike on the wire which is coming from the pick up White/Red and Blue
New Ignition coil and both Spark plugs were Ground.

[Striker1423]

Short to ground somewhere along the wire. Check your points for grounding. Broken insulators, misaligned etc.

[1976RD400C]

I would check for a voltage spike with a meter on the red to brown and then the green to brown wires as you kick it. That will tell you if the source coils that charge the cdi are trying to work. Your ohm readings on those coils seem ok as you previously measured. If you get a reading that they are trying to charge, and the pick up coil seems to be doing it's thing, and the coil is new, then I think you got it down to a bad cdi unit.