If they are the black plastic covers, yes it would be likely that just the o-ring gaskets are leaking.
But there is a problem. Kohler has discontinue these o-rings. You must replace the covers with the new stamped steel covers. They are installed using Permatex Ultra Black RTV and 4 shorter screws per cover.
When removing the covers the screw next to exhaust ports especially will likely be galled in place so be careful with these you need work them back and forth lots of times to get them out. It likely that they may break off during this removal then you need drill the broken portion using step drilling process so you stay as centered as possible. Then resize to tap at 7mm-1.00 (plug tap) and install new appropriate screws. When tapping apply rubbing alcohol to the tap to prevent jamming and breaking it. Don't use any oil like Tap Magic. Also remove the tap a few times and remove the chips.
Also depending if your engine has adjustable rockers or not. If adjustable the clearances should set before putting on the new covers.
Notes on using RTV. The mounting surfaces must be oil free. This means if oil is puddled in the rocker arm area of the head it should be removed by soaking it up with paper towels. Here I use the Permatex surface prep but a suitable cleaner can be used to oil from the contact surfaces. Once oil free surface apply 1/16" - 1/8" bead around the cover contact surface. Install the cover being carefully not to smear this bead. Finger tighten the screws. Now wait 24 hrs before final torquing the screws to 65 in lbs. DO NOT START the engine during this curing time. The reason is that if any oil that contacts the RTV before it cures it will cause it to not cure properly; actually prevents the curing.
Yes the service manual say wait 30 minutes but it doesn't work. I did a lot of resealing covers by following those instructions. Then I found the curing time is 24 hrs per the RTV instructions. Sure saves a lot time when you follow instructions.
