Not sure if this belongs here, figured I'd post it anyways.

A little backstory: I work on a farm, where this ATV was once a trusty workhorse. But at some point, problems led to it getting a new piston, but for whatever reason, it's knocking and hitting valves, and it was deemed not worth trying to fix again. This led to it being scooped up and abandoned in the junkyard here. After a few years sitting on its side, with no spark plug, events led to me deciding to buy it for $50, because, "why not" expectations, along with price, low. It was over by that blue tub, flipped on its side. I had to drag some stuff away to even get to it. Rough, but intact. Overall the frame and equipment is in good shape, one of the footboard pegs was bent, nothing a hammer couldn't fix. Suspension feels decent. Headlights work.

 

The engine did spin, and with a new plug, does have strong spark. Hell, I'm pretty sure I got it to sputter, but obviously it didn't run.

The crankcase was full of water, so I drained it, and flushed some oil and mineral spirits through it. Note, the engine did have good compression, but would sometimes feel REALLY stiff, like throw your back out pulling it over stiff. The starter could barely turn it, even with 40 amps, unless I blocked the intake. A teardown was in the cards from the start.
The carburetor was really nasty, looked like curry inside. I didn't bother cleaning the jets, and just got a cheap rebuild kit. Fuel tank was clean though.



Now for the notoriously tough to remove clutch, yeah, that was about as easy as you can imagine. I figured I'd be needing a new one anyways (foreshadowing?)

I tried the, "hydraulic trick" with grease and the clutches reverse threaded bolt... Stripped some threads clean off the bolt in the crankshaft, yippie. This also meant I couldn't buy a clutch puller and do it right, due to the threads being blocked.

I tried everything I could think of, from chaining a sledgehammer to it and aiming for the moon, to attaching my winch and sending it with my truck. Nothing.





I ended up shattering the outer part with a hammer, then the spider, that I used a hammer to unscrew, THEN I was able to jam something under the inner part and smack it until it flew off.

Minor damage to the crankshaft seal seat, but considering what I had to do, I can live with that.

Secondary came off easy, I'll be reusing that.

 

With delicate persuasion from hammers and prybars, I was able to get the engine disassembled, mostly so I could clean the junk out of it.


Looks better than I expected, but still not good

Most of that came off easy.






Unfortunately, all the banging around broke the piston skirt, so I'll be ordering a new one of those, I think I'll go ahead and get an .030 and send the cylinder to get properly bored and honed, vs hammering one in and hoping it runs. Do it nice or do it twice.

There was some aluminum pieces in the oil slurry, they match the piston machine marks, but must have been in there for a long time, as they were not from the piston I broke. Some of the bearings were crunchy and stuck, so I thought I'd need to replace those.

Seasoned mechanic here told me to just clean them with some diesel and put a little oil in there. I was skeptical.

All bearings are smooth and spin freely now. You learn something new every day.


Well, here is the current state of my engine, most of the parts are in surprisingly good shape, but need cleaned.

 

If anyone has a motor for a Warn A2000, I'd be interested in buying that off you, this Prairie has one, but the motor is junk. Gears look fine, could use some fresh grease though.