Here are a couple of YouTube videos showing how not to treat a 3-valve twin, or any other motorcycle for that matter.

The first is just engine abuse, there is obviously something very wrong with the valve clearances, cam timing, ignition timing or carburation. Here's a quick tip; if your exhaust headers start glowing red hot you should probably not continue to rev the crap out of the bike.


And here we have a 400 twin running with no headers at all, presumably to enable the operator to see flames. I won't list all the reasons why this is just wrong. It does sound rather comical though, like a popcorn or bubble blowing machine.