GrizzlyMan660 asked how to remove the engine from a 660 and I went ahead and created a new thread so we would hijack the original one.
GMan, if you look at this pic from my garage, you will be able to see a bit of what you'll be looking at when everything is out of the way.
Note that it is almost impossible to get the engine out with the front wheels on so you will need to support the frame with blocks or an ATV jack like I have in the pic. You will also need to remove pretty much everything from the engine...hoses, carb, wires & connectors. You will also have to pull the front and rear drive shafts by removing the front diff mounting bolts and rear drive mounting bolts and pulling the diff & drive out enough to get the shafts out.
Once that is all done, decide if you want to remove the CVT cover. When I yanked the engine from the wife's grizz, I did because I needed to clean / rebuild the CVT anyway. Doing so also has the advantage of getting the cover out of harms way and, if you pull the primary sheaves, gives you the primary shaft as an extra handle for guiding the engine out.
To do the actual pulling, it takes at least two people unless your pretty darn burly (I did it but I liked to put a serious hurt on myself). Unbolt all 4 engine mounts from the engine side. If you have an engine hoist or similar, you can use it to lift the engine out of it's mounts and then unbolt the mounts from the frame (they get in the way). If you don't have a hoist, you will have to man-handle the front off the engine up and then block it or strap it up to the frame so you can get the mounts out and then do the same in the rear.
Once the mounts are out of the way, the entire engine/tranny assembly has to be rotated so that the cylinder gos down and the tranny end goes up in order to fit through the side of the frame. This can be tricky. Again, if your burley enough, you can just grab it, rotate, and pull it out but, it's over 150 lbs so, it ain't easy. A better option might be to run two pipes or 2x2 boards through the frame and strap them to the front and back of the engine. You could then have two people, one on each end of the pair of pipes lift the engine with the pipes, rotate it, and slide it out one side. A third person to help guide / coax the engine out would be a bonus.
To put it back in, reverse the procedure. Keep in mind that you will have to block or strap the engine up in the frame so you can re-attach the mounts to the engine after it is in the frame and then lower it back down to attach the frame-to-mount bolts. Don't completely tighten any of the mount bolts until they are all in and just snugged down...then torque to proper specs.
Mine: '02 660 now in custom Hammered Copper paint
Mods: Custom air box mod for big-o' clamp-on K&N, Dial-A-Jet, 26" BH 2.0's on ITP SS 106's, SuperTrapp IDSX exhaust, Maier fender flares, black Ricochet skids. Remote res. Works A-T Steelers shocks on all 4.
Hers: '04 660 LE (Ruby red)
Mods: same A/F mod, 1.5" billet spacers with BH 2.0's on stock wheels, Yami aluminum skids.
That which doesn't kill you, leaves scars to remind you not to do it again