Engine seizure - 2000 Suzuki VL 125 Intruder LC

You probably can't. The additive broke down the oil that is in the fuel that lubricates the engine. This causes the overheating and the seizure. You now have a hunk of slag, not a chainsaw.

un-seizing an engine successfully will depend on what has caused the lock-up
if it is a hydraulic lock then removing the plugs will fix that problem
however if it is ring seizure in the bores from severe overheat then you may have to consider breaking up the piston in bore to fix
if it is a bearing failure that has seized the engine then the bearing cap will have to be removed
the way to go is to pull the engine and make sure that the seizure is not from torque converter, flex plate failure or transmission failure
consider replacement engine because a seizure generally means a more costly repair than an operational , low mileage motor from the wreckers

fuel filter, computer

So what is your question about computer operating systems?

check for engine seizure by trying to turn the crank nut by hand / wrench If you cannot move it either way the it is a new engine / replacement engine

by locked up do you mean that you cannot move the crank shaft at all If that is the case then lack of sump oil will cause bearing seizure or loss of coolant will cause piston seizure. IF the timing belt broke it may be locked from the valves not allowing the pistons to move past top dead re

Hi Dean, Sorry to tell you this but as far as I know it does not shut down. If the engine overheats it is more likely that a seizure or partial seizure will shut it down.Overheating can also result in damage to the cylinder head or the gasket under it. Regards John

Your discription sounds like the engine has a seized piston or two or three. Pull the head and look and feel inside each cylinder. The cylinder walls should be super smooth and have no scratches. If a wall is scored up then a seizure has happened. Seizures are due to excessive heat. A lack of two stroke engine oil in the gas is possible as well as a bad water pump. NGK BR9ES is the stock spark plug.

The damage that can result from overheating an engine would be piston seizure. Without the cooling water circulating around the outsides of the cylinders to dissipate the heat from combustion, the piston temperature rises higher and higher. As the piston(s) get hotter, they expand. Being aluminum, they expand more than the liner of the cylinder does, and eventually expand to a size bigger than the cylinder. That is when the seizure happens.
At this point, you need to do a compression test on all 4 cylinders. You should have at least 150 psi on each cylinder. Anything lower than that is indicative of a problem.

try to spin the pulley with you're hands or a tool, if u cant spin it the engine probably froze because there was no oil.