How hard is it to put rings in a 04 250ex? The reason I ask is because I let mine sit for 3 years without running it. And now it smokes awful and puts oil out the exhaust. It still runs great and don't make a noise so it has to be the rings stuck or something. Would the seats gone bad cause it to smoke like this? And I have rebuilt my banshee multiple times and the last time I built it I tore it all the way down to put a new crank in it. Are the 4 strokes just as easy to rebuild?