Small Engines (Lawn Mowers, etc.): Draining Battery, negative battery cable, engine model type

Question
Hi Eric, I have a 24 horse B&S OHV Intek engine on my craftsman tractor. I went to start it the other day and had nothing. I replaced the battery with a new one and it started right up. After 6 days, went to start it and the battery was dead. Exchanged battery for a new one and it starts and runs great but will it drain the battery again? If it does what is causing this, Is there an alternator? What keeps it charged if there is not? What am I looking at as far as cost to either fix this or have it fixed? Thanks alot.

Answer
Start with this link:

http://engines.myfaqcenter.com/Answer.aspx?p_faqid=3438&body_0$tbKeyword=alterna...

http://engines.myfaqcenter.com/Answer.aspx?p_faqid=26&body_0$tbKeyword=alternato...

Check the alternator to make sure it is charging.

Overall, the alternators and flywheel magnets are pretty reliable.  Once in a while a diode or regulator will fail.

http://engines.myfaqcenter.com/Answer.aspx?p_faqid=1401&body_0$tbKeyword=regulat...

You will need a multimeter and I like to use an inexpensive 12 volt test light.

I have found bad diodes by dis-connecting the negative battery cable and installing the 12 volt test light in series, one end to the cable and the other end of the test ligt the the negative battery post.  If the light "lights" up with the key off then there is a drain on the battery.  

You can send me the engine model, type and code number and I can if your engine has a regulator.  The Craftsman model number, format xxx.xxxxxx, could also be helpfuel.

Let me know what you find.
Eric