Most Mexican insurance policy's do not have any medical payment on them, make sure you have a policy with an evacuation clause in there so if any thing happens they will get you back to the States, most of the normal policy's will have this but the real low cost ones don't.
$300,00.00 is the lowest you need to get now but they recommend $500,00.00 and it is not much more. ( I am going with the 300.00.00.) If you think you may be there for a while the difference between a two week policy and a 6 month policy is not a lot.
You must have the original registration to get a temp import visa for your bike a copy of the registration will not do.
If you are going down soon you must stop and see the whales, one of the only places in the world you may get to pet one of these massive mammals swimming with their new born calfs. It amazing ! I have been to four different lagoons and had the best experience out of San Ignacio. $50 from the town in a van ( you can ride your bike) 4 hours on the lagoon, and an all you can eat buffet when you get back to the dock.
The whales are the main reason I am going next week again.
Don't think, go ! You will have a great time if you take normal precautions.