There are two in the front and two in the back on my 225 one of the ones in the back is hard to see and requires removing an access cover on the lower cowling. It will help if you have extensions for your ratchet socket wrench. You may also have to remove the wire bundle hold down to totally remove the bottom pan. If you are just changing plugs dont remove the wire hold down just separate the halfs a little and push the back down enough to give you straight line access to the plugs.Irv
.
