After putting new pads on my slip clutch after I burnt them out I noticed oil leaking out the side plug. I thought that was weird. It was sitting in the sun and not running at all. I opened up the side plug and oil began spilling out. Probably around a 1/4 to a half pint of oil came out of the plug hole. Only thing I can figure out is it was overfilled at some point. To be honest, I don't think I have ever put any oil in it since I bought it and that was probably 4 or more years ago. Anyway, number 1, I am wondering if the vent plug is working correctly. I removed it and when I push on the underside of it, it moves up and back down. Perhaps it is dirty on the inside and not letting air escape?? Not sure what is going on. The side vent plug was very tight so I am sure there had to be a great amount of pressure built up for it to be leaking out there. Just don't know if I need to replace the vent plug or not. Guess it wouldn't hurt. Also, shouldn't the oil level be even with the lower part of the hole on the side plug? Do you guys ever try to replace the oil or do you just make sure there is enough in the gear case? Thanks for your help! This is on a SQ160.