Arcing coils / Running issue / no top end

[73 sport]

   I've had Dyna coils and distributer plate on my '74 Sport since the mid '70s. never a moments problem. I have silicon rubber plug caps, the insides are lightly coated with silicon grease. The coil caps are also coated inside with silicon grease. Many of the gripes I've seen on this site looks like rain, humidity intrusion. Not all ignition wires and caps can handle higher voltages produced by performance components. The complainers seem to have similar problems, they don't want to spend the money for quality components.

[baloo]

Yes, Any update?
I'm having the same problem of backfiring at higher rpm - I have the Dyna system, which ran great until parked about 1yr ago. 
Thinking it might just be the coils (Dyna 5ohm) which test out OK per static tests with multimeter.
I'm thinking the coils just might peter out at high rpm (when I get backfiring - around 6000rpm)

Carbs cleaned out

[73 sport]

    Go to Google. Type in "What causes backfire at high RPM".

[Turin]

It's not the Dyna ignition or the coils. Both have been swapped. Not the carbs either, those were swapped.

IOt has to be the NGK (racing) plug wires

[michaell32]

Weak valve springs cause this issue. The valves could be floating it the high rpm.
Edit: Nevermind. You already answered the other comment.

[Turin]

Some of my issue is the F@$K A$$ 2-1 pipe. Hail Mary pass, swapped a Rennsport 2-1-2 system from my stash and Voila... The bike revs to 8K with no jetting changes. Got more tuning to do, but this is a step in the right direction.

[turboguzzi]

Glad to hear you seemingly found the culprit.

Not sure an "exahust system issue" would have been top of my list, but one of the reasons i asked you for pics of the whole bike is that sometimes the problems is there staring at you.... :)

Now that i see it fully, wow, nice tool! some good goodies on it too...

[Tkelly]

Nice collection!

[Turin]

That's not my Garage !!! Mine is loaded with old guzzi's.

[Offcamber1]

Rodent nest in the 2 into 1 pipe???

[Turin]

nope. A rodent nest might have helped by adding back pressure.

[Turin]

it revs quickly to 9K, pulling hard past 8k. Next item of business is to modify the bottom of the fairing, as the under oil pan exhaust takes up that real estate.