Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Make and model? Application? If engine ran out of oil, it ma have internal damage. Is this gas engine? Remove spark plugs and see if engine will turn. Can you get a wrench on flywheel or crankshaft nut to see if it is seized?
sp170subaru 3000psi looks to be pressure washer. Engine is likely seized from lack of oil. Remove the recoil housing and get to the flywheel to see if enginecan be turned with wrench. If it can be moved, remove the spark plug and put oik in the cylinder and turn with wrench till it gets as free as it can. Then re-install the recoil /starter assembly , spin engine to clear the oil, then re-install the spark plug and see if it will start.