Help with my 5400 Kohler (please)

[NativeGardener]

Ok, longtime listener, first time caller here...

I have a 3 year old Craftsman T210 with the Kohler 5400 series engine - 18HP 541CC. Here's the high level:

• It is running ROUGH (sputters, not much power particularly when the blades are engaged)
• hard to turn over - even replaced the battery, which helped a little, but turns a lot before it engages
• can't have the throttle all the way up to "rabbit" setting (it chokes up at that level vs revving high like when it was new), I have to leave it about 2/3 up
• replaced the oil, oil filter, and the air filter - no improvement

A few folks have suggested it might be the carb? Is this something I can easily fix/replace myself..? (I have tools, but this would be new for me).

Thanks for all advice/help!

 

[Rivets]

I’m suspecting a blown head gasket or valves out of adjustment. This manual should give you an idea how to proceed. https://resources.kohler.com/power/kohler/enginesUS/pdf/22_690_01_EN.pdf