My uncle recently gave me his old fabuglas boat with a 50hp johnson after he upgraded. It had sat for a while so I had the carbs rebuilt and the water pump replaced. It ran perfectly until one day I was out cruising, and the engine began to hesitate and surge and then lost almost all power after about an hour and a half on the water. It would not go above trolling speed even when given full throttle. However, after sitting a couple of days, I took it out for a test run and I got it to plane out though it would not reach top speed and the engine would still surge a little. After letting it sit another week, I took it out again for about 45 minutes, and it ran perfectly. I then took it out a third time, and after about an hour and a half experienced the same problem. When the problem occurs, turning off the engine and sitting for even a few minutes will allow you to plane out and run normally for a few seconds after restart. Any suggestions would be greatly appreciated.
