I've got a 2005 27hp prodrive Kohler. I bought it used last summer and have been plagued with numerous,but small, problems. I'll list them below. Thanks for any help.
1) After I first bought it, the idle was too low when I put it in gear it would eventually cut off. I took it to a repair shop and now it idles too high and when I put it in neutral after running, a lot of the times it revs up high again in neutral. I've gotta shut it off and re-start it to get the idle to go back to a level I feel comfortable putting it in gear. I've tried adjusting the idle screw on the carburator, tightening the arm that goes to the throttle, and putting in a stronger spring. Could I maybe be missing a spring?

2) The plate that mounts to the side of the motor to hold the oil filter is leaking at the connection. I put a new gasket and plate on there but it still leaks a little.

3) I had to put on an extension on the pd for my boat. After doing that the lower unit seal right below the extension started leaking. I got a guy to change the seal and it worked shortly, but now it's leaking again. The guys at pd think I need a whole new lower unit. I don't have the funds right now so I was wondering if anyone has fixed this themselves.