Preparing engine for restart

I'm not sure what type of engine you have but I'll make some general recommendations.

There are 2 primary issues to be concerned about. The first is the condition of the fluids. Of these the 2 most important are fuel and oil. Oil will acidify over time and can wreak havoc, not to mention it can gather water and essentially thin out over time. So drain that (you'll have to do it for the second issue anyway). Most diesel, depending on additives, can sit around for a long time without any issue. Gasoline cannot. I once got a killer deal on a 3 year old Passat that wouldn't start after sitting around for a year or so. Bought the car, towed it home, drained fuel system and refilled and it started up first turn. So drain the tank, the fuel filter, and carburetor (if equipped). It will take a few extra cranks to get the fuel system purged and the good fuel to the engine.

A word of note if it's carbureted: If the fuel sat for 9 years you may have left a varnish inside the carburetor. If so it'll need to be disassembled and cleaned. Soaking in new gasoline works well, but it'll still likely require some scrubbing to get clean. Also, regardless if it's injected or carbureted, if it's a gas engine get some appropriate fuel system cleaner and add it to the gas after you're finished.

The second issue to be concerned is lubrication. As mentioned you'll need to replace the oil. But more important is to lubricate the camshaft, crankshaft, and piston rod bearings. I can't stress this enough. This is the #1 cause of engine failure when restarting motors that have sat round. You may start it and get lucky, but I wouldn't chance it.

When an engine is operating normally, the oil pump injects oil under pressure to the camshaft and crankshaft bearing journals. This leaves a very very thin film of oil on the bearings that keep them from sticking and thus galling. If you've heard someone talk about "spun bearings" this is what they're referring to. To prevent it, you need to get access to the bearings and apply a thin layer of oil or molybdenum grease to the surfaces. On a typical 4 cylinder car this would mean taking off the valve cover, disconnecting the camshaft timing belt, removing the camshaft and lubricating the bearings, then reinstalling, making sure the timing is correct. Then remove the oil pan, and remove the crankshaft and piston rod bearings one at a time, remove the bearings (thin metal sleeves) and lubricate the crankshaft side only, then replace and retorque. Replace the oil pan, replace the oil filter and engine oil and restart the motor.

If it sounds like a lot of work, it is. Some people have tried all sorts of things to get around it, including injecting oil under pressure through the oil system. It isn't very successful, though, as once the oil film dries up the metal bearings are fitted under such close tolerances that they wring together and won't allow oil between them.