T head engine by Brian

[Sparky_NY]

I noticed a interesting observation in your video. Watching the exhaust, its clearly visible that it is mostly clear then there are occasional "puffs" of smoke, the cycle repeats. I am wondering what is causing that strange exhaust behavior, ignition misfire, fuel building up somewhere?

[brian Rupnow]

Simple answer--I don't know. The carb could be tuned a bit rich.