Hi I hope someone can help me. The 1998 cylinder on pto side had something get into the cylinder and it made a bunch of like ink pen end sized dents in the head and on top of piston. The ring seemed to be alright, thinking maybe a chunk of ring broke and caused the problem. The jug looked pretty good (no gouges or groves or scratches) so I bought a used head and piston just to see what would happen. Well same thing I took both jugs off and there was quite a bit more play in crank bearing on pto side So it being early in the season I picked up a 2000 MXZ 700 and rode that. I happened to run across a whole 1997 motor on craigslist. I had someone pick it up for me and the case is different between 1997-1998 mainly from what I can see is the ignition is different. Which can I change stator from one to the other? The pickup coil is in the same spot. Also I am wondering if the rotary valve timing is different? There is another difference there is a hose barb that comes out near where the wires come out from the stator. It is at a 90 degree angle facing the pto side. I have the shop and parts manuals for both engines and I cannot seem to see what connects to it. I tried to blow through it and I can. Is it some kind of vent for the area around the flywheel? So I am wondering if someone could point me in the right direction? Or would know of someone here that would know? I am new and don't know what to do? Your help is greatly appreciated!