You can do it in any order but you'll need to make sure the fuel supply is clean and un-plugged. This will probably necessitate pulling the gas tank & cleaning it, checking the lines, kitting or replacing the pump (sometimes you get lucky & don't have to do this) and kit the carb. Check the points, plugs & wires. Make sure it has enough oil & the oil doesn't have water in it (IMHO even better would be to change it first). You can temporarily delay the fuel system clean & check by using a remote fuel source such as a lawn mower gas tank to route fresh gas directly to the carb for a test start (if your carb doesn't need kitted). I'm sure there's something I've left out that someone else will add. STRONG CAUTION: Never, ever use old gas. The reason checking & cleaning the fuel system is #1 is because old gas can stick your intake valves shut after you shut the engine off. The next time you try to start it you can bend pushrods or worse. Don't ask me how I know this. frown


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