What is a one stroke engine

There is not any one stroke combustion engines.

There r four stroke engines also known as a 4 cycle engines, & two stroke engines also known as two cycle engines. These engines r common in small engines & in car engines. There r also five stroke & six stroke engines that r not very common.

Four stroke engines have four strokes:
intake (induction) stroke
compression stroke
power stroke
exhaust stroke

In the two stroke engine, operate in two strokes, instead of the four strokes.

Power/exhaust: This stroke occurs immediately after the ignition of the charge. The piston is forced down. After a certain point, the top of the piston passes the exhaust port, & most of the pressurized exhaust gases escape. As the piston continues down, it compresses the air/fuel/oil mixture in the crankcase. Once the top of the piston passes the transfer port, the compressed charge enters the cylinder from the crankcase & any remaining exhaust is forced out.
Intake/Compression: The air/fuel/oil mixture has entered the cylinder, & the piston begins to move up. This compresses the charge in the cylinder & draws a vacuum in the crankcase, pulling in more air, fuel, & oil from the carburetor. The compressed charge is ignited by the spark plug, & the cycle begins again.

- STB

No such animal. 2 stroke will fire each time the piston compresses, this is the up stroke, the down stroke has no fire, just expanding gas to deliver power. A 4 stroke engine fires every other compression or upstroke.
2 strokes are less expensive to make, and are smaller HP, like a lawnmower. 4 stroke are typical car engines, more expensive and more powerful.

one stroke and it dies?

A normal reciprocating (piston) engine cannot really have one stroke since the piston must always have a return, or second, stroke back to the top of the cylinder, where combustion occurs, to continue powering the connecting rod to turn the crankshaft. However, this does not apply to engines such as gas turbines which have a single continuous combustion pressure acting upon vanes causing direct rotary motion to the drive shaft, but l am not sure that u could describe rotary motion as a 'stroke'. Maybe rotary engines such as those made by Mazda could be said to have a single stroke, but l think that is stretching it a bit.

On second thoughts, a piston engine with combustion at each end of its travel through the cylinder with a drive rod in its centre would be a 'one stroke engine' if air induction & exhaust were incorporated within its stroke, but maybe thermal efficiency would suffer, as it does in many 2 strokes. But this only really applies to internal combustion engines. Maybe this arrangement works better in a steam engine with steam pressure acting on each end of the piston at the end of each stroke, so there may well be one stroke steam engines out there.

An oar.

BR 549 is right, except even with oars you need a''two stroke'' to go in a straight line. hahahahaha

its a 2 stroke with a bad cylinder

no such critter

4 cycle and 2 cycle or stroke.

you mean a rotary engine, like a wankel?