Hang in there. Working on it yourself will give you migranes but it can be done. Me for example, I have a 742B skid steer with a Mitsubishi 4G32 engine. This engine was made in the 70's ( I thought it may have come with the skid steer when they built it in 1993) but, I'm not to sure that was the engine Bobcat installed in them back then. I also get an awkward look when I tell some mechanics it's a Mitsubishi engine in my skid steer. Maybe somebody knows what they mostly installed in Bobcats back in the 90's. Anyway, after getting quotes for somebody to rebuid my engine, I was getting quotes of anywhere from $5,000 to $15,000 for a rebuild. And I was told how hard it is to get parts for constantly! But I am lucky enough to have a mechanic friend who offered me to use his garage, his tools and his advice for free. I was pretty nervous about it, being I have never rebuilt an engine in my life. But he assured me it I could do it. So I have already pulled the engine, tore it down, cleaned the engine and the engine bay which was full of dirt and grease and oil, honed the cylinder walls and now am awaiting the parts to be shipped to me, which took me over a week to find. I had number 1 cylinder with broken rings and number 4 cylinder with broken rings. I was blowing oil so bad that you couldn't see when you fired it up inside. I knew I was in for some work on it. But, I dove right in and have been tearing it down and getting it ready for about 2 weeks. With some good support, if you've never done it before it can be done. Just take your time, label the heck out of everything or take pictures as you go and use the resources on this site to help you. Good luck. It's possible!