ok so I have a 2000 sporty 1200 evo. Nothing has been done to this bike proformance wise. Before I got it my step mom rode it and she had over reved the engine causing a gasket to start leaking with about 10k miles on it. It was fixed. After I got it I put drag pipes on it to make it noisier, and it did. Needles to say I was putting in a parking lot and all of the sudden I lost compression on the rear cyl. I had bent a pushrod. Got it home and tore it down to find the valve guide seal on that head was so bad that my valve stems were stained brown n black but the front head was not like that. Now my ole man shares I bent the push rod because I didn't rejet the carb. And it was caused by putting the drag pipes on it and their not being enough back pressure. Im told no that something bigger has gone wrong in the block but I've put it back together with stock pipes and so far so good. Does anyone know if putting drag pipes on my stock 1200cc 2000 sportster would cause the valve to hit the piston and inturn causing the pushrod to be bent? It was on the exhaust valve that did it but I was reading about back pressure and ppl. Are saying backpressure is a wise tale. If anyone can shed some light as to whats going on here it would be appreciated. Thanks in advance and God bless.