Hello, I have a John Deere 717a with a 19HP Kawasaki on it. It seems to be hard to start sometimes. Not only when its cold, but during the day when it has just been ran. I has just turned 250 hours. I'm not a mechanic by any means, but I understand the basic principles of an engine. Do you think the valves need to be adjusted? This is the first thing that comes to mind for me. If not, any other idea before I take it to have it looked at.