What size are the bolts on a 1990 skylark 2.5 starter

Can you turn the engine by turning the alternator or water pump ?
If the engine turns freely, could be a problem with the cables to the starter or the starter itself.

There are only 2 bolts. They go straight up through the starter motor housing into the engine block. You may have some plastic covers that go around the starter and flywheel area that will need to be removed to get to them.

that must not be original motor maybe. I'm sure there can only be two or three diff motors. take old one in with you and pull all avail starters for that car and match it up.

at the end of the positive battery wire.

disconnect battery,,,jack up car,,(put jack stand on frame)) remove starter wires,,then starter bolts,,

remove the two bolts, pull out and replace.

It is not that hard and should take about 30 minutes. You will need to jack up the engine a few inches before you take the bolts loose from the starter. You will need those three inches to pull the starter out. It needs to fit between the frame and the engine block and it will come right out. After you pull the starter bolts and starter wires.

engine size please?

Did you try starting it in neutral? could be park neutral switch. or ignition switch.

yes you can you can gnerally find then at the auto parts counter at the dealership or at NAPA, Oreillys, or AutoZone. please rate this. thanks