TOPIC:

I have a 1980 LTD1000. 29mm smooth bores. Dyna S ignition. 3 ohm Andrew coils. 

Bike started running rough, changed plugs, no difference.
Eventually it only ran on 2 cylinders. Now, won’t start at all.

So, I cleaned and installed new needle/seat, floats, gaskets on carburetor. 
Still won’t run.

Checked coils, all within specs.
Conpression, 100-110 on all cylinders.

Spark plugs have a nice white spark dead in the center.

I poured a small amount of fuel directly into one cylinder and nothing.

Completely baffled.
 

possibly a timing issue.

Are you getting spark at all? Kinda sounds like your dyna-s took a dump. 

Spark is white and dead center of all plugs. When I called Dyna I was told, “if you have spark, the ignition is good”.
I am calling this afternoon to Dyna to see if I can send it to them for testing.

 

Are you running the Dyna S directly to the coils or are you still using the stock exciter? 

I have the same bike.  Several years ago I had problems with two cylinders not running.  It was an intermittent issue that made it hard to trace.  I eventually concluded it was either the exciter or the stock ignition so I switched to Dyna S and 4 ohm coils.  I stripped out the exciter as well and wired the Dyna S ignition directly to the Dyna coils.

1980Ltd1000 wrote:

Spark is white and dead center of all plugs. When I called Dyna I was told, “if you have spark, the ignition is good”.
I am calling this afternoon to Dyna to see if I can send it to them for testing.



 

Sparking inside they cylinder is a different thing to sparking outside where there is less pressure, what is the supply voltage at the ign+ side coils ?

Still have the exciter on the bike.

I suspect the exciter is the problem.  You should be able to wire your ignition to your coils directly.  You will need to follow the Dyna directions.  I don't like the coupler they provide for providing power to the ignition (red wire) so I just extend it and plug into the spare brown double female receptor near the headlight.l

Yeah that blue scotchbrite connector is a failure waiting to happen 

I'm on vacation right now so I don't have access to my bike to take photos.  But from memory I think there are four wires going into and out of the exciter but only three wires coming from a Dyna S ignition.  To wire directly to the coils there should be a green and a black wire.  One goes to one coil and the other goes to the other coil.  Just match the colours.  The third wire is the red one that needs to go to a hot wire.  I use the spare brown but you could tap into your red starter wire as well.

hardrockminer wrote:

I'm on vacation right now so I don't have access to my bike to take photos.  But from memory I think there are four wires going into and out of the exciter but only three wires coming from a Dyna S ignition.  To wire directly to the coils there should be a green and a black wire.  One goes to one coil and the other goes to the other coil.  Just match the colours.  The third wire is the red one that needs to go to a hot wire.  I use the spare brown but you could tap into your red starter wire as well.

Black and Green = Coil triggers
Red = Ign live
Black/yellow = Ground
PS: did you ever check the supply voltage at the coils ?

 

Trying to eliminate the box now, will respond once I do with results. Thank you for the help so far.