I just purchased a used pontoon boat about 25 years old. It runs good for about 1/2 hour then seems to slow down. if I give it more gas it picks up for a little while then bogs down till it finally stalls. I then have to prime it again to start and it then wants to keep stalling There are 2 gas tanks , i switched to the second tank and had the same problen no matter what speed i go. If i keep priming the motor i was able to get it back to the dock. I am a newbee to boating any help in this matter would be appreciated.
