An engine requires gas and spark to fire but it also requires compression and timing. If it has gas and spark, I would check the compression...should be over 100 to run good. If it has good compression then I would check to see if the spark occurs when the compression does. If it doesn't then you probably have a sheared key on the flywheel.
because its on fire
Does it have fuel/ compression?
appears no fire going to spark plugs
Is it getting fuel? Does it have compression?
sounds like the glow plugs need replacing
Its probably your timing chain or belt
It's probably the battery is dead. doese it have gas and fire
check your coil out
Does it have spark, fuel, compression?
It's overheated, probably. unless you have matches in there
carb. adjustment, fuel filter or the engine is shot.
it could me bad fuel ..or fuel pump