Hello, I just bought a 1987 Ariens GT20 with a Kohler Magnum 20hp engine... I've looked around quite a bit on this forum but can't seem to find if this m20s passes the test of the die-hard GT fans... I'm hoping that it's a great motor and last a long time. I change the oil every 25 hours and the filter every 50 just like recommended. It's been well cared for by it's original owner and has almost 8000 hours on it, although you would never know it to look at it. Is this motor popular or is it one of those, "Oh no it's an m20, to bad."...