Was trail riding this weekend and kept having stalling issues and then failure to start. If I jumped off battery it would start, but if I was just idling for a while it would die. Voltage on battery after it diedown would be around 10.5 to 11 volts. I played with tension on belt, if I made it tight I would get a God awful squeal. I noticed the alternator was putting out about 12.4 volts. My understanding is it should be around 14volts. Is this correct in assuming? Is my alternator going bad? Thanks in advance.

Testing an alternator with a voltmeter can be challenging, because the voltages observed can change significantly.

Ideally you want to start with a freshly charged and known good battery, as this has a major impact - with the engine off you should be seeing somewhere between 12~13V (measured at the battery), and with the engine started, this should increase by 1~2V, so you should now be seeing 13~15V - add some load, lights, fan, etc., you may see a slight drop, not more than 1V or so, and then bring the engine rpms up to around 2000, and if you're still seeing that 13~15V, the alternator is probably good.

The above procedure checks the charge rate more than anything else, and it IS possible to see everything I have described and still have a defective alternator - you will not see AC ripple caused by a shorted diode, and if the alternator is overcharging because of poor regulation, the test will not reveal it.

A dead battery (one cell shorted) will show 10.5~11V just coming off charge, (2.2V/cell x 5 = 11V) and the alternator will try to charge it, which is evidenced by the 12.4V - which is the 1~2V increase I mentioned - replace that battery with a known good one, or charge it fully, see if it comes up and and then retest.