If you bought the boat new you should be fine. I have dealt with my local shop several times now. Go online and find your local MK service center. All they need is a copy of your bill of sale. They told me I could make a copy and black out all of the prices if I wished. Just make sure the bill of sale has a date. That is really all they need. I asked them about the registration card that was sent in and he told me that doesn’t really do anything. The only time they use that info if for recalls. Anyway they will want your bill of sale and they will use the serial numbers off of the motor. They should get you all fixed up. It is a lot easier to go through the authorized service center than MK. Be sure to get it in, as it sounds like you are nearing the end of your warranty.
Mk is very good about standing behind their products. I owned a Genesis several years ago. When people started having problems with them they offered a trade in program. They allowed us to trade in the Genesis on any MK motor we wanted. Every problem I have ever had has been taken care of and has never cost me a dime.
If you need any help I could get you in contact with the MK rep for your region.
Jason