Question about motorcycle performance for serious mechanic only.?

Your 535 virago should pull top gear easily at 60mph. It will be in the power and torque range that it feels strong. Reading your question it certainly sounds like there is a problem with your bike. I can't tell you what the problem is; there are lots of possibles like a seized centrifugal advance where the ignition timing is permanently at the idle setting instead of increasing the timing as the motor revs increase. A loss of compression due to normal wear with use on the piston rings and valves leaking. Even a dirty air filter will reduce a motor performance.

So what would I do, firstly take the bike to a Yamaha shop and ask fir it to be test ridden for the fault you have, then have it diagnosed and a quote for what they advise. Next is optional; have it dyno tested for torque and horse power, if it is down under spec then have the work done and retested on a dyno if you still feel it hasn't got the power after the work is done.

If you don't have the time or skills to at least diagnose the problem it is well worth a visit to your closest Yamaha workshop. Hope that helps you.... A well worded question and would like to hear the results, hit my avatar and drop me an email....