Alright, so the other night I was riding back to my buddies house. When I got on it pretty good, I heard a pop. After I heard the pop my bike sounded like a tractor almost, kind of as if it wasn't firing on all cylinders. I barely made it back to my buddies house because I couldn't keep enough power to actually ride it so I ended up pulling the choke and riding the clutch in first gear to make it the last half mile.

Today I bought new spark plugs, and put them in thinking one of my spark plugs fouled out being as they had not been changed since I bought the bike last May, and I don't know the last time they were changed before then. When that did not solve the problem, I checked and made sure I was getting a spark from all 4 plugs, and I was.

After that, I unplugged each spark plug one at a time to see which piston was not working. When I unplugged the spark plug in piston one & two, the engine would not even start. Then when I unplugged the spark plug in piston three, the engine would start and run just like as if it were plugged in. Am I correct in assuming that mean piston 3 has something wrong that is preventing my engine from running correctly?

I had someone check it out who has been working on engines for quite some time, and he told me that he thinks I broke my push rod or bent the exhaust valve in piston three. Does that sound like it could be the problem?

 

I would do a compression check on each cylinder and that should give you an indication if you have an internal problem.

 

I had a similar thing to happen to me, rolled on the throttle and heard a loud pop/pffft! I took the bike to the Dealer, blah, blah, one jerk Tech said we need to do a complete diagnostic check, motor work (scam). Another Tech fixed it in 30 secs. Turns out it was a vacuum hose. Small hose under tank and fuel connection. Hard to reach, unless you have small hands. He used "forceps" and pressed back on. He said it was common. Popped off 1 or 2 times later. I have 34K + miles since that time. Hope that helps.