I have 2 bikes and on of them will pop after being run hard. The other one has only popped once, but on a top speed run you can see occasional flames. Currently, I have to run the bike really hard, usually up a long hill, and hold in the kill switch while WOT and it will pop a few times. However, I have a new idea. I want to mount a spark plug in the exhaust. I will place this about 2/3-3/4 down the muffler. The muffler is gutted to about halfway (My "quiet" bike). I have a coil like unit that can run off of a 9 volt battery that indeed fires a plug. I will open the spark gap substantially. The goal is to be able to hold the kill switch and a small momentary switch, or tie the 2 together, causing raw fuel to be pushed into the exhaust and ignited. Don't tell me its a bad idea or could cause damage as it is my last summer before college and will be my last summer with the bikes. btw the coil thing I have is a cheap unit from ebay that claims to generate 80,000 volts and can throw HUGE sparks (over 2 inches). When i hooked it up to an old plug, it was an insanely bright spark even with the gap increased. Any input?