Have a Lund MR Pike 2005. Some times the gas gauge gets stuck reading full when its not. Is the float stuck or is it a sendding unit?. Is this someting that need to be looked at asap or can it wait till fall.

Its more then likely the fuel sender unit. They are inexpesive units and fail from time to time. My bets are is that if you replace that you'd be on your way.

The unit is more prone to stick if it is the older wire float style. If its newer post '05 ish then it will be the ring float style which sticks much less.

How much fuel do you use before it goes off of the full mark????
Or does it never move down?? Your tank is probably 27 - 32 gallons.

On my 1700 Angler, it stays on full until I have used about 12 gallons
or more. Then, it goes down quickly from that point.

I you do a search on fuel gauges, in general, you will find this is a common for
most boats. Many posters on WC have installed fuel flow sensors to get
an accurate reading of fuel consumption.