first off, what type of sled are we talkin about, year, model etc.
the sled just stopped.
is the motor seized(can you pull it over) or did it seem like it ran out of gas.
now to me, i cant believe that someone would sabatoge your sled(unless you said somestuff you shouldnt of)
i take it this isnt a four stroke sled, so you can start by checking the colour of the oil you are running, you gotta think what this stuff might look like if mixed with antifreeze.
it sounds to me like you have a blown gasket which allows fuel, and oil to enter the cooling sytem.,(head, base, crankcase etc)
check your oil reservior to see if you can see antifreeze, or if it seems like you used a lot more oil then you normally do.
now in some cases old antifreese will gel up. and should be flushed out of the cooling system., but i havnt herd of cases where it changes colour( again check what colour of coolant is in your sled)
