Small Engines (Lawn Mowers, etc.): 25hp Kohler command carb setting?, exmark lazer z, kohler command

Question
My engines Model is CH25S I think it's a 97. It was running bad so I did a complete tune up, changed all fuel lines and rebuilt the carb. This carb has a fixed main jet. I can't get the rpm's past 3400 at idle. With blades on the rpm's drop to 3300. They should be 3600 with blades engaged. Oh this is on an Exmark Lazer Z lawn mower. I moved the setting on the governor but it didn't make much difference. Any ideas? I used 10-30 oil as the manual recommened.

Answer
I'm not intimately familiar with this engine but I can tell you of two ways to adjust the governed engine speed.  There is  either a screw to increase tension on the governor spring or the governor spring itself needs to be changed.  I recommend you contact a Kohler service dealer if you need more information.  Hope this helps.