barry68v10 wrote on 12/31/69 at 16:00:06:Ok, that's not that radical. You may not like the unintended consequences of completely eliminating "backfires after I shut it off." You may experience poor "hot weather" performance and greatly reduced MPG. Backfire, or more accurately "post ignition" is part and parcel with an efficiently tuned single. My bike gives a modest "poof" on shutdown and is turning in just under 70 MPG on the highway.
You might try 1 heat range cooler plug, or decreased spark plug gap of .005-.007 inches, and see how you like it.
I concur. I live with the after killing "blurb" on both Dyna equipped bikes. As long as I don't get shotgun blasts at any speed or shutdown, I'm not to worried about a bit of popping and spitting. Though I have minimized it a lot through fine tuning on one bike. I got lucky on the other one, and it sounds/feels like someone jetted it correctly. From the more even pull, they perhaps even got it more spot on than I did the first Savage!
As for plug heat range changes, I wouldn't wade into a hotter plug unless it was an extreme case of last resort.