I just started my shovel this week after a complete rebuild. It was a basket case, but still is good shape and all there. My current observation is this:

Bike starts right up and runs at 1100 rpm just fine.
With my hand in front of the muffler, the front cylinder pops regularly and with a nice strong push of gasses.
With my hand in front of the rear cylinder muffler, I get a good pop but also getting a miss.
Compression is 145 in each cylinder.
New points and condenser on a new plate.
Front cylinder never misses
I attached a timing light, and I can see the miss on the strobe coinciding with the miss I hear.

I have not observed and ground path for the spark plug wire to the rear cylinder - no obvious shorting
I swapped spark plugs, wires and coil - No change
Timing is set to static at this time - I have not done the 2000 RPM timing yet.
The rear cylinder fires on the larger breaker cam side (broader cam)

So it's an electrical problem as the timing light strobe reveals

Am I missing something?

 

so little info for a clear answer

and if you have not ridden it for a 1/2 hour to get the cob webs out and re adjust the carb while hot and drive it again - your trying to fix something that might not even be broken

again light info - first harley -- not clear on the engine is not 180 degrees apart in firing - so it mimics a potato potato sound and exhaust skip

 

Both plugs fire at the same time..

 

Are you trying to troubleshoot the "miss" at idle that occasionally breaks the engines cadence? If so, dont bother. They all do that...

 

Yeah they do... It does sound like many I've heard, but the miss on the timing light (when simply watching the strobe - not on the timing mark) made me think something is wrong. The miss is synced with the timing light missing a flash. I'm still waiting for a dual cable throttle to show up for the S&S Super E, I'll break it in next week and do a final timing..

 

Yep, the coil fires both outputs every time with single points. Thanks.

 

You said you cant see any plug wire issues? (Shorting) Have you checked that in the dark?

 

Have never used a timing light on any Harley... but... remember since both fire at once... you can get fire Not on the mark as well as On.. ie 45 degrees apart...
Do Not overthink this ****!!!
Go Back to Johnjzjz's post... and breathe

 

I didn't check in the dark.. Will check.

 

Thanks... probably right on that.