With the spark plugs Removed... You need to see if you can turn the engine over By hand...
You either have:
1. Engine seized, locked up and can't turn.
2. Starter jammed in or at the flywheel, or just completely shorted.
3. Solenoid Not energizing the starter, you can jump across the 2 Large terminals with heavy wire to check this.
4. Your Not getting 12 volts to the starter for some Other reason. Measure voltage While experiencing the solenoid chatter.
It has to be one of those 4... :smile:KennyV