Hi Lorax. I sold my 490 about 5 years ago and have regretted it ever since. I tried racing it against modern bikes but it couldn't handle the huge jumps they litter the tracks with these days. Oh and the front brake had about the same effect as putting your hand sideways in the wind.But that engine would whip everything other than a 500 Honda or Kawasaki 2-stroke but even against them the Maico generally gripped better out of the gate. One of the best things I've experienced in life is going from 3rd to 4th on the Maico on a long start straight and passing modern 450 4-strokes like they were 125s. After the race riders would come to look at the "piece of junk" they had sneered at earlier to see what was going on. All they got to see was a sand cast air-cooled engine without a single trick on it, not even a reed valve and couldn't work out how something so simple could make so much power.(Yes I do know about the KTM 495 but they had a hit in the powerband that turned grown men to jelly)
Starting it was no problem as long as it was jetted right and you used the decompressor but there was a knack. Once hot I could start it with my left foot from the seat no trouble.
My advice would be if you're not sure about parting with something cherished: DON'T