Recent events have caused me to rethink selling the Airhead; primarily getting out for a 130 mile ride Saturday. The important thing is that I am going to keep it. And with that decision I need to do some work. First issue is a possible valve spring/seat issue, at least that is what a friend recommended. Why? Well, the first symptom is that after about half a mile at 80 mph it starts sputtering and losing power, he said I was floating valves. The engine is slow to rev, but this may just be normal for a small engine and heavy flywheel. It also seems that I really have to push the bike to get it past 55-60 mph, even 65 seems like a struggle. I also get some smoke out the left tailpipe if the bike sits on the side stand for a couple of hours. Valve clearance is correct, I set that about 1,000 miles ago and have had the problem as long as I've owned the bike. I do get the nice little sewing machine tapping so clearance should be good. Carbs are balanced. Finally, I get pinging at lower rpms and big throttle openings. As far as I can tell the timing is correct. I'm not sure is this is connected to the first issue or another problem entirely. I do have a timing light with tachometer. If I understand the process correctly, the timing is set properly. Any work I've done I reference a Clymer manual for the /6 models. And for what it's worth, the odometer show 43,099 miles. After this we will move on to suspension issues.