Small Engines (Lawn Mowers, etc.): power fuse blowing with regulator connected, power fuse, altenator

Question
I have a mower with a 25 hp b/s intek twin v engine. As soon as I turn the key on it blows the power fuse. There are two yellow wires from the altenator to the regulator and one red wire from the regulator to the charging system. I can disconnect the red wire and it will run off the battery without blowing the fuse. I can reconnect the red wire and disconnect the altenator (yellow)wires to the regulator and it will run off the battery even with the red wire plugged back into the charging system. I have the correct voltage (28 vac)coming from the altenator when the engine is at full speed with the yellow wires disconnected. I read no voltage from the regulator with it connected to the altenator and disconnected from the charging circuit. What I'm not sure about is which is my problem. I read 0 ohms through the altenator, but I also read 0 ohms to the engine case from either of the yellow wires. Is the altenator supposed to have a short to the engine case? If so, is the regulator my problem?

Answer
 Hello Tim:

 If you are Reading Voltage from the Stator and you Read No Voltage from the Regulator While the Engine is Running, then, the Regulator has Shorted. The Regulator should show 13.0VDC to 13.5VDC when the Regulator is Working. Hope this Helps. Let me know what Happens, Please.

 Good Luck

 Respectfully

 John