I am trying to get my father's pontoon up and running. It is a 92 model Grumman pontoon with a 92 model, 40 hp Johnson outboard motor. The pontoon has seen little use for the last several years, due to dad's declining health, and eventually his passing in May of 2012. Took it out last week-end to check things out, but there is a problem that I need help with.
Made one trip that probably was roughly 3 to 4 miles long, running at 3200 rpm's and everything went fine.
Made a second trip later in the day, a little longer in length, but not by much. As I got to about 1 mile from house, it sounded as though the motor suddenly revved up. As though the prop might have come out of the water. Was running in smooth water, so that was not the case. For the rest of the trip back to the dock, any time the motor got over about 2000- 2500rpm's it would do the same thing.
The last time (several years ago) I had the pontoon on the lake, the same thing happened, so this is not something that has just started. Then, when the boat had sit overnight, it would do fine the next morning for a while, then motor would rev up, and you would be limited to about 2000 rpm's till you got back to dock.
My first thoughts were that something was slipping in the lower unit, or prop was slipping for some reason.
Any thoughts and/or ideas on what the problem is, and how to fix would be greatly appreciated.
bert-nc
Made one trip that probably was roughly 3 to 4 miles long, running at 3200 rpm's and everything went fine.
Made a second trip later in the day, a little longer in length, but not by much. As I got to about 1 mile from house, it sounded as though the motor suddenly revved up. As though the prop might have come out of the water. Was running in smooth water, so that was not the case. For the rest of the trip back to the dock, any time the motor got over about 2000- 2500rpm's it would do the same thing.
The last time (several years ago) I had the pontoon on the lake, the same thing happened, so this is not something that has just started. Then, when the boat had sit overnight, it would do fine the next morning for a while, then motor would rev up, and you would be limited to about 2000 rpm's till you got back to dock.
My first thoughts were that something was slipping in the lower unit, or prop was slipping for some reason.
Any thoughts and/or ideas on what the problem is, and how to fix would be greatly appreciated.
bert-nc