Geez...I had the same symptoms with My Boyer sytem last year(Some might remember...LOL)...I ended up going back to the points,just to see if it would make a difference,and to hopefully stop the incredibly loud backfiring...and it did.My engine was apart for most of the winter for a rebuild and upgrade(cams,carb and pistons),so now I'm wondering if somewhere during the whole process,that maybe the same thing happened to Me,and it got over-looked?I tried SO MANY different things,and pulled so many hairs during all of this...WOW!
The bike ran perfectly BEFORE I tore it all apart,and as soon as I put it back together,that was when it all started.And I CHECKED the order of the wiring over and over again!...ALL of the wiring.What's strange though,is that I set it up the same way that I did when I originally installed it...where it worked great!
I re-read the instructions,and NO...I wasn't drinking when I re-installed it.The backfiring was unbelievably loud...in fact...One of My Neighbors thought I had finally snapped,and SHOT My bike!LOL...seriously!
I ran the whole season with the points,because it WORKED...and I wasn't about to pull it all apart again,and kill even MORE of My season.I now have a Dyna2000 system about half-way installed,and I'm pretty sure that I'll get good results from it.
Typhoon...welcome to KZR,and thanks for shedding some light on the whole thing.I now have to wonder if maybe the order of the power-supply wires were the culprit.I contacted a Boyer Supplier,and asked about coils,and I was told that I could use the factory coils on My 77 KZ1000,so I did...and originally it worked flawlessly...the next season(after the engine rebuild)...the exact opposite...hmmm...I have always wondered what could have happened,and why it wouldn't work after My rebuild.The module had never been dropped,and was treated like GOLD,anytime I worked near it.
So My 1-year-old Boyer system might still be usable,and in perfect condition?...Oh well...I'm sticking with My Dyna2000...much nicer,and more User-Friendly.LOL
Where the hell were You LAST year,BTW?!!