LA360 Octane
Anytime you are doing any engine diagnostics you must begin with a good, fully charged battery
(minimum 12.5 volts).
Lock the throttle blades open by just putting a large/long screwdriver down into the secondary side of the carb.
Label and remove spark plug wires, Blow off any dirt around spark plugs.
Remove and set plugs aside in proper order.
Remove coil wire completely. This eliminate possible shocks to you.
Insert proper sized compression tester plug adapter and gauge.
Hand tighten.
If you don't have an assistant, use a remote starter switch to rotate engine.
Rotate 4-6 rotations. Do the same amount for each cylinder. Record the number for each cylinder.
If more than a 10-15% difference between cylinder readings, further diagnosis required.
Normal is between 125 - 175 p.s.i. depending on engines c:r.