If that is a single cylinder Courage, you will gave a crack down the exhaust side of the crank case near where the cylinder meets it.
Before you do anything, contact Kohler with your engine's serial number.
Some will get a replacement short block but it will have to be done through a dealer so will cost you some money.
JB seems to hold up pretty well.
It weeps a bit ( well all mine have ) but some I did 4 years ago are still running quite fine apart from the fact they weep up to a pint of oil from under the patch between services.
One is used by a sports club and mows about 3 acres of the outfield weekly during in season.
From here on in, make sure you check the oil regularly and check the bolts eash season when you remove the blower housing to clean the fins at the end of season.
thanks I'm not going to put too much more money into it. I got it used year, and the plan was to get something new this upcoming spring. I just need it to last for about another few months of this season and into next.
It is interesting to see that yours held so well. My repair seems fine, but I have a new problem
Blue locktit is what the factory fits and blue will do.
If you use red you need to heat the cases before you try to remove the bolts.
You may have worn the front threads to the point that they will not hold when hot so either helicoil the 4 front ones or go up to a larger size bolt.
IF you want to make it a NASCAR mower you can always drill the bolt heads and fit lockwire
Other than that decide if the mower is worth a replacement engine.
thanks for your help on this
another totally random question, but how easy is it to fit another engine on there? The chassis looks like it has a bunch of engine mounting holes under the engine. how much do new standalone engines typically go for (southeast US region).