Check spark getting to spark plugs, check petrol getting to carburetor and then to cylinders.
Sounds to me like petrol supply or ignition problems.
If it's a diesel engine then maybe fault with decompression system.
If not check state of spark plugs and gaps.
Could also be flooding if not starting after many tries I guess.
Once started does it drive and keep going perfectly well or not.
If you spray Engine Start (product to start recalcitrant engines first time) into the carburetor via the air filter does it start immediately?
Remove air filter and try a start without filter, old engines clog up air filters with oil from positive crankcase pressure due to leakage around worn piston rings.
All things to try to understand what problem may be.
Cranking is just an electric motor (starter motor) being correctly connected to the flywheel and turning the engine over, there are other vital details required.
Sounds to me like petrol supply or ignition problems.
If it's a diesel engine then maybe fault with decompression system.
If not check state of spark plugs and gaps.
Could also be flooding if not starting after many tries I guess.
Once started does it drive and keep going perfectly well or not.
If you spray Engine Start (product to start recalcitrant engines first time) into the carburetor via the air filter does it start immediately?
Remove air filter and try a start without filter, old engines clog up air filters with oil from positive crankcase pressure due to leakage around worn piston rings.
All things to try to understand what problem may be.
Cranking is just an electric motor (starter motor) being correctly connected to the flywheel and turning the engine over, there are other vital details required.
It's not the least charm of a theory that it is refutable. The hundred-times-refuted theory of "free will" owes its persistence to this charm alone; some one is always appearing who feels himself strong enough to refute it - Friedrich Nietzsche