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-   -   No spark on trailing plugs (https://www.nopistons.com/1st-generation-specific-16/no-spark-trailing-plugs-73313/)

dansf100 10-21-2009 11:45 PM

So, my '79 with a bone stock 12a has no spark on the trailing plugs. Any idea's here? Let me just say, I have NO experience with rotary engines, so please talk to me like I'm a novice. Thanks.

jon103a 10-23-2009 02:09 AM


Originally Posted by dansf100 (Post 835103)
So, my '79 with a bone stock 12a has no spark on the trailing plugs. Any idea's here? Let me just say, I have NO experience with rotary engines, so please talk to me like I'm a novice. Thanks.





hi, ignition system on a gen 1 is basically the same as any other, just doubled up. i have only just got my fb so i am not sure if yours and mine(83-a) are exactly the same. first off is always physical damage, anything look broken, contacts inside cap, rotor arm, leads ect.next would be the coil packs themselfs( i assume you have two like mine) at the low tension side (outer terminals) you should have a live ignition feed- this must be same as battery voltage, only check with ignition on not cranking or running as the voltage will go up to 200-300volts. the other side is earth from your igiton system this controls the dwell(coil charge time) if you have a good posative on the other terminal you can flash this terminal to earth and should see a spark. if not check the coils with an ohm meter and check they are the same aprox resistance or you can just swap them to see if the problem moves to the leading plugs as a quick test of the coil itself. let me know what you find, jon.

dansf100 10-23-2009 10:37 AM

So when you say to check the coils themselves by swapping them to see if the problem goes to the leading plugs, you mean physically swap them in their positions in the double mount and swap all the wiring etc correct? Not just leave them where they are and swap the hi volt coil wires from one tower to the other and vice versa? Right? Hope I'm explaining myself clearly.

jon103a 10-25-2009 04:55 AM


Originally Posted by dansf100 (Post 835142)
So when you say to check the coils themselves by swapping them to see if the problem goes to the leading plugs, you mean physically swap them in their positions in the double mount and swap all the wiring etc correct? Not just leave them where they are and swap the hi volt coil wires from one tower to the other and vice versa? Right? Hope I'm explaining myself clearly.





hi, if the low tension wires are long enough ( the two outer wires on top of the coils) and you can swap them without moving the actual coils then thats fine, as long as you swap all the wires you dont need to unbolt the actual coil packs. the coil packs are always a weak point on any system as they get hot and will fail in time. you can also swap just the king lead(the ht lead from the coil pack to the rotor cap to eliminate that, just make a note and remember what goes where, although the cap should be marked. L= leading(bottom plug) t=trailing(top plug) so L1 on the rotor cap is leading plug 1 which is front rotor bottom plug, ect. if its not the coil pack it gets a bit more involved but with a half decent multi meter i am pretty sure you can sort it with a little help, jon.

Kentetsu 10-27-2009 09:22 AM

You might want to just start with basic tune-up items. Cap/rotor/plugs/points. If the points are worn or burnt, that could explain your problem...

dansf100 10-28-2009 01:17 AM

I did a tune up on it when I first got it a few months back. Cap, rotor, plugs, wires, filters fluids. Didn't change the points or condenser on it though. Maybe that's a decent step to take as well. It's got a duel point set up in it right?

jon103a 10-28-2009 08:12 AM


Originally Posted by dansf100 (Post 835241)
I did a tune up on it when I first got it a few months back. Cap, rotor, plugs, wires, filters fluids. Didn't change the points or condenser on it though. Maybe that's a decent step to take as well. It's got a duel point set up in it right?





i take it it ran ok after you serviced it?. did it just die or did it run rough before it packed up?.


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