I re-assembled my 01 zr 800 recently, has ported 900 jugs, billet head, reeds, slp pipe etc. I took it out riding yesterday, was holding its own against my piped 05 zr 900 my 120 lb LESS than me Son was riding. We drove about 50 miles flawlessly, pulled into a little gas station and topped them off with anticipation of riding another 50-100 miles, it had warmed up so I leaned out the dial-a-jets a few settings. Took off and within 3-4 miles of the gas station sled would no longer rpm to 7800, was hitting 7500-7600 and had a miss, WTF I was thinking as whole motor is fresh but has been blown up more than once . I looked at the plugs, looked fine NO ALUMINUM , jetted it back even though I knew it would not make it break up. Took off, sled was now hitting 7300-7500. Decided to head for the trailer before things got real ugly, as I headed back it got worse and worse, would barely pull 6000 towards the end, sounded just like a sled does right before it seizes. I kept thinking I must have gotten a tank full of crap gas and water but I only pumped in 4 gallons and the 05 got the same stuff and was still running fine??? Stopped several more times and checked/ changed the plugs looking for any signs of aluminum. I got to the trailer and shortened the plug wires and re-did the plug caps, no difference. I then pulled the coil off the 05 and put it on my sled and took a quick rip down the trail, was turning 7800 again with no hint of trouble, I have never seen a bad coil act like that and progressively get worse but I thought I would post this in case someone has same symptoms and can't figure it out, Smitty