Kohler k241a Rebuild
 

Hey guys,

I started having more time to work on the cub lately and I ended up buying a kohler k241a spec 46407D. I bought it with the intention of getting it completely rebuilt and cleaned up, and swapping it with the engine currently in my 105. According to the previous owner the engine ran but he couldn't remember how well. The piston is stamped with an arrow has some kind of number on it that starts with "ms" followed by a bunch of numbers. It isn't stamped oversized which hopefully means its standard, right? Anyway, I plan on tearing it down and taking it to a machine shop to have the bore checked, overbored/honed if necessary, the valve guides and seats checked, and the crank checked for spec. I'll have pictures posted a bit later and I intend to keep the thread updated as I progress with rebuilding it.

I started taking apart the block, so far I have the pto off, valves out, flywheel shroud off, camshaft cover off, and the breather assembly off. I plan on pulling the flywheel this weekend or Monday once I rent a puller for the job. Here are some pics of it. Looks like it'll need reboring but I'll know for sure once I take the block apart completely and take it to a machine shop.

Here's a pic of the bore. Now just curious I noticed behind the pto the block has some blue paint on it, it's the same spec as the Kohler currently on my 105 but it's odd that it would be painted blue behind the pto but yellow everywhere else. Is that normal or would that be a sign the engine didn't come from a cub originally?

It needs bored.

I wouldn't worry about the paint color. Who knows what it was in. Something else probably used the same spec number. Just curious, what was wrong with the original engine that you don't want to rebuild it? Like Jon said that engine needs rebuilding, no question.

The original engine was bored out to .030 already and is glazed so it would've set me back more to have that resleeved, the machine shop quoted around $100 plus cost of the sleeve. This engine is std, as far as I know, since its not stamped over sized (has an arrow stamped on it) so I can just have it bored out. I'm gonna hang onto the original engine and rebuild it at some point in the future.

All pistons have an arrow or a notch in them. It indicates how to install it.

Well I was expecting the block to be std since the only stamp on the piston is the arrow, lacking an oversize stamp. From what I read and know, oversize pistons are stamped to whatever size they are .010, .020, .030, this one lacks that which is why I think it may be std. This is my first rebuild though so I don't know much (but am hopeful to learn). Is my thought process logical or could it still be oversized since it isn't stamped std? If anything I'll find out once its apart and at the machine shop.

It is likely standard since you don't see any numbers on it.

Update:

Alright so I rented a harmonic balancer puller from my local auto parts store and tried to pull the flywheel off, ended up bending the bolts that came with the puller. So I bought 2 grade 8 bolts and got it off. I also have the bearing cover off, and pto. I was looking at taking off the pto bearing and pulley. I took the screws out of the bearing and the pulley. I'm guessing a jaw puller has to be used to remove the bearing? Pics to follow