Kohler seems to supersede part numbers with regularity. I would not be too worried about the replacement part number not matching the installed part. Sometimes new parts are specified, but the assembly line uses what stock is left in the bins until they are gone.
As far as the plastic cover, assuming the shroud, you want to be sure that the shroud still helps deflect cooling air over the cylinders and will not flop around. You may be able to drill out the original bolts/cap screws, and re-thread with a larger size if necessary. I don't know if there is more 'boss' area that you could drill and tap to install screws in a slightly different spot from the factory original. If you drill into fins, you don't run much risk unless you start to break them. You would have to be careful for other spots, or drill in the original. You will have to judge. There are 'left hand' drill bits that can remove stubborn fasteners if used carefully. Just put the drill in reverse, and drill into the center of the fastener, slowly. It may come loose with just the force of the drill bit, so go slowly.
tom

 

Kohler seems to supersede part numbers with regularity. I would not be too worried about the replacement part number not matching the installed part. Sometimes new parts are specified, but the assembly line uses what stock is left in the bins until they are gone.
As far as the plastic cover, assuming the shroud, you want to be sure that the shroud still helps deflect cooling air over the cylinders and will not flop around. You may be able to drill out the original bolts/cap screws, and re-thread with a larger size if necessary. I don't know if there is more 'boss' area that you could drill and tap to install screws in a slightly different spot from the factory original. If you drill into fins, you don't run much risk unless you start to break them. You would have to be careful for other spots, or drill in the original. You will have to judge. There are 'left hand' drill bits that can remove stubborn fasteners if used carefully. Just put the drill in reverse, and drill into the center of the fastener, slowly. It may come loose with just the force of the drill bit, so go slowly.
tom

Hi, is the engine out of the tractor? If not how the heck did you get the shroud off? I am in in the process of replacing a coil while the engine is in the machine and it looks like this is impossible. Thanks

 

Replying to my own post here, but I just found that Kohler references 24-584-45-S for this engine:

Kohler Engines Parts - engine parts for service, maintenance and repair

Part number 19 in the parts list.

Still not sure why the tractor has the -25 part, but looks like I'm safe to use the -45-S part.