How should an engine be started that has not run for 5 years?

I had the same problem and what we did was get rid of all of the old gas in the tank because if it sets too long, there will be varnish in the tank. After that, if it is carbuerated, make sure you spray it with plenty of carb cleaner. Then you change the oil and filter. Marvel Mystery Oil is really good for the gas and the oil and you can get that at Oreilly Auto Parts. We then changed the plugs,wires, fuel filters(primary and secondary on a carbeurated engine)and put the marvel mystery oil in the oil and the gas. Next, you fill that sucker up with some fuel and put some down in the carb. If its anything like my adventure, it should start up just fine but with some white smoke. HAHA hope that helps you some!

you should put some marvel mystery oil in each cylinder and turn the engine over by hand.. Of course you have to remove all the plugs first and leave them out until you get the engine ready. let sit for an hour and repeat the process. Make sure the water and oil are changed. after you have repeated the oil in the cylinders three times. You are ready to try and start the engine. check all wiring and battery for proper function. turn the engine over with the starter. Replace the spark plugs (recommend new ones) and then try to start the engine.

The best way to start any engine that has been sitting for any time longer than a year is to flush the old gas out. Gas that has been sitting for too long will go bad unless a gas preservative was added to it. Then change the oil and the oil filter. The coolant in the engine block, and the radiator should be flush out, and only clean water she be added without the thermostat. A lot of sediment from the iron in the block and from the radiator will build up and the coolant. This a also a good time to examine all rubber parts for cracks or leaks. It's would also a good time to change the spark plugs and wires. Examine the carburetor make sure its that it free of debris spider webs or any thing else. It would ofnot hurt to change the fuel filter pre-carburetor. All this with a fresh battery, and lots of luck you're good to go.

try adding kerosene in oil and turning flywheel over manually with socket at the front of motor where the fan is,this might free up the motor if it started to seize