stroh 0 Posted April 26, 2016 I have a adco allis 918h with kohler ohv 18hp motor that has developed an oil leak in the front of the engine. At first I thought it was a head gasket , but this engine does not have individual heads like most garden tractor engines. I removed the muffler cleaned the front of the engine and it looks like there is a Valve cover sitting right in the middle of the engine and that is where the leak is coming from. I have order a new gasket and a valve reed of some sort. My question is has anyone had experience with this engine. And if so is this a job that is not too complicated . I am somewhat handy but I am not a mechanic. Thanks in advance for any help Story Share this post Link to post Share on other sites
PhanDad 3,622 Posted April 26, 2016 If your engine doesn't have heads, then it's probably the Kohler OHC "Triad" engine. I don't have any experience with this engine (except replacing them), but a failed breather valve can cause oil leaks and blown seals. So the parts you have ordered may fix the issue. Hopefully someone with more knowledge than I will respond. And, IMO, if you do in fact have the OHC engine, you should do Al's mods to keep your engine from dropping a sleeve and cratering. Share this post Link to post Share on other sites
Bill725 1,177 Posted April 26, 2016 The engine is a Kohler Triad OHC engine. There is a piece of spring steel/shim stock used for the reed breather. After many hours of use the spring steel breaks and needs to be replaced. You will have to remove the plastic valley and replace: 1)breather grommet, which goes in the block, 2)reed breather and 3) breather cover gasket. Clean the cylinder cooling fins before re-assembling. Share this post Link to post Share on other sites