To seize, as taken from Webster's means: to cohere to a relatively moving part through excessive pressure, temperature, or friction -- used especially of machine parts (as bearings, brakes, or pistons). To fail to operate due to the seizing of a part -- used of an engine.
These parts cohere due to a slight melting of adjacent components. This occurrence can destroy an engine, in part or in total.
Piston seizure occurs when there is no lubrication between the cylinder wall and the rings. This can be caused by insufficient oil in the fuel mixture or by excessive heat breaking down the oil. Your engine can overheat for a number of reasons, but the most common is a lean running condition or overloading the engine with too much weight. There are two main types of seizures, the soft seize and the hard seize.
A soft seize is a type of seizure that occurs when there is insufficient lubrication and/or the piston overheats and expands to the point that it gets stuck in the cylinder. It usually frees up immediately or soon after the engine cools. Very minor piston smearing is a typical sign of a soft seize.
Please see this discussion for more information on soft seizures.
Soft Seize Poetry
When soft seizing you will hear,
The motor goes waaaa ka ka klink.
The sound it makes is very clear,
The clunk you feel is very distinct.
When you ride hard on a nice cold night,
Or take your filter off on a real hot day.
Your motor starts to strain and fight,
Yap yap yap it calls in dismay.
And then all of a sudden,
You gain 5 miles per hour.
And you start to wonderin',
From where came this power?
Well that my friend… its the last little bit
Of life you are squeazin' from that brand new kit.
If only you’d listened when your bike cried,
“Hold the fucking choke down and pull to the side.”
“Now take off your shoe and give me your sock,
Put it over my filter and tie it.
We’re going home, slow as shit.
But hey at least you don't have to walk!”
Wow, I'm blazed.
Poetry by Harold
A hard seizure occurs for the same reasons or under the same conditions as a soft seizure. However, hard seizures cause more damage to the piston and/or cylinder, and the parts may remain seized and stuck together even after the engine has cooled down. Scoring in the cylinder, missing nikisil, and aluminum smeared across the piston rings, and/or loss of compression are typical signs of a hard seize.