The oil pan gasket on my 27hp verticle shaft kohler is leaking again. The gasket leaked near the oil filter right at 300 hours. I was told 10 days was the soonest the gasket would come in so i made my own from paper bought from Advanced. It worked for about 12 hours and now it leaks again a few inches away once warm. Is this a common problem? What is causing this? I now think it may have a warped block or oil pan. If warped i may try to machine it and use a lot of high temperature rtv. Any suggestions?