Overheated 700 edge rmk

Sounds pretty bad. I'm not quite clear though, did it run until it seized up, or was it shut down before that? If it ran until it seized, then I wouldn't be surprised if it needs the whole nine yards – cylinder re-plating, pistons, rings, heads and deck trued. Not sure on the bottom end, but that's more likely to be ok. Whatever the case, you'll have to tear the top end apart to figure out what's needed. Closest failure to this I've seen is a burned piston on an old Indy, so hopefully someone else can give you a better idea of what to expect. Unless you're lucky and can get by with just pistons and a hone, you might want to look for a used motor. If you want to kill two birds with one stone, swap a 550 fan motor into it; maybe three birds if your kid can start it himself!

Not enough information to determine the cause of lockup. Pull the plugs first, and see whether it turns over. If it turns over without resistance, then put the plugs back in and see if you can start it. If the primary clutch can spin the crank between certain resistant points, then rings are toast and are hanging up on the ports. If the primary clutch cannot be turned at all, it could either still be the rings that have become damaged and melted the piston, or a crank bearing went. If the primary clutch has a lot of play in it at the outside seal, then the PTO crank bearings are shot. The O-rings in the cylinder head, may also have melted or blown. That tends to do damage to the piston, rings and cylinder walls when water gets into the combustion chamber. You would have to take the entire cylinder head off in order to inspect the O-rings and pretty much everything else. The coolant circulates around the cylinder head walls and cylinder head, and not so much in the walls of the crankcase. So the damage is most likely in the cylinder head area due to the tight tolerances for rings, pistons and cylinder walls. Probably need 2 new cylinders, 2 new pistons and 2 sets of new rings. Remanufactured cylinders is what you would be buying.

Another cause for overheating is the nylon lock nut that holds the water pump impellar down on the axle, backs out and eventually contacts the water pump cover and slows the water pump causing reduced coolant circulation and freezing of the impellar as it hits the bottom of the cover and strips out the inner hole at the axle.

Before panicking I would raise the front of the sled to get the cylinders straight up and down, take the plugs out, mix a little bit of gas in some injection oil and put a spoon or two in each cylinder. Let soak a bit and then work the clutch back and forth to help loosen things up. One of the pistons will likely be lower in the cylinder and will need the oil treatment a few times because it will run out the ports.

I think once the cylinder got hot the oil film got too hot and the dry piston just stuck. Good chance that you might want to freshen rings and pistons even if you get it running, but I really doubt you lost the jugs. It does not take much to stop an engine that is idling.

Cost me $1800 when I overheated my 2003 800. I'd pull part the engine and see how bad it looks, can't really know how much it will cost till you do that. Rebuild it yourself if you can, it will save you a lot of money.

You have to do the work yourself. Because a blown engine essentially totals a 700 Vertical Edge. The cost of repairs could be about equal to its value when fixed. If you cannot do the work yourself, you either part it out and try to sell the expensive parts, or you sell it "as is" to a used parts dealer.