Want to rebuil mtd 159cc ohv engine

New to the forum. I have a 3 yr old(bought new) Cub Cadet sc300hw push mower, with a MTD 159cc ohv engine. Up till now its been a great mower, small yard so, it hasn't seen a lot of use. Starts on the first pull and does everything I could want. Mowing a section of the neighbors yard yest, I hit a big root in some taller grass and bent the blade, went and got a new blade, when I started mowing again, I noticed it was leaking oil very badly out of the front of the engine.. I would like to attempt a rebuild myself, just need a video or book on how to. I can work on auto engines pretty easily, so I am handy with tools and a little know how, just never attempted a small engine. I have searched you tube for a video on the engine, but can't find one on the exact engine I'm looking for. Any pointers and advice will be much appreciated. Great forum btw and thanks in advance....

Probably needs a seal (gasket?), or at worst something cracked.
I'd be a little reticent to do a rebuild just to find out it still leaks.

Yeah, I'd like to tear it down before I start ordering parts, just looking for some good videos or reading on the tear down and what to look for....

We will need the brand name and number off the engine. With that we can probably get you a service manual and point you in the right direction.

The first image is off the side of the engine and the second one(serial #) is off the rear chute cover. Hope this helps.

Ok, still not sure of where to find information on the engine, but I removed the engine from the frame and this is what I found:
The engine was slightly loose on the frame,
When I got the engine and air filter, carb out of the way, I seen where it looked like oil coming out from between the bottom(oil pan?) and the block of the engine.
Taking the oil pan off, I discovered a missing bolt where I found the gasket to be broke:

I also found the pulley/blade shaft on the vertical shaft to be bent(not sure if it is supposed to have a seperate key, or if the bend is a built in key),

another pic,

So, a trip to the cub cadet dealer Tuesday to get the parts I need(I hope).

Still a little confused on the engine model number vs the mower model number, I know it is an MTD engine. Here is a stamping off the engine block itself. Is the first set the engine model number?


Thanks for all the help in advance, wasn't as hard as I thought it would be. I didn't see any cracks in the block or pan itself, so hopefully just a gasket and new bolt for the pan, new carb gaskets, air and gas filters...

The first set of stamped numbers is the engine model number. the key in the pulley/blade mount is built in. Looks like somebody hit something solid and then I would be concerned about bent crankshaft, or the blade has been run loose causing damage to the key.

Ok, I think I found it, it is a 5X65RU MTD engine...

Thanks ILENGINE, I hit a big root mowing part of the neighbors yard. The crankshaft looks(the best I can tell) straight. I was able to find the engine diagrams online and found the gaskets, bolts and other things I need, BUT, I cannot find the pulley/blade shaft in that diagram. Would that be specific to the mower itself? Thanks again..

Found it. Lord, this is worse than the old stereo instructions...