99 johnson 25hp water pump

[Dannycompagno]

I'm trying to figure out what is causing my outboard to stop pumping water once I have been running on plane for about 2 mins. While idling and when I first take off it pumps strong but after running wide open for a couple mins it stops and when I slow down to an idle it starts circulating again. Any suggestions on what I should check or change is appreciated.

 

[flyingscott]

The hub in the impeller could be slipping or there is no key in the impeller. I would lean towards the hub is slipping in the impeller.

 

[racerone]

2 cylinder or 3 cylinder ?------Post the model #

 

[Boobie]

Is the impeller housing sealed correctly ??

 

[johnnygjr]

Drop the l/u and inspect water pump impeller,housing,water tube,grommets Etc. When she stops pumping is she overheating?An infrared digital thermal gun 20.00$ at harbor freight would come in handy. a little more history would help. was a new pump installed? Is the engine new to you? Engine installed at proper height on transom?

 

[racerone]

The 3 cylinder motors do not use a copper water tube.

 

[johnnygjr]

Who said it was copper,those were only generic instructions,guidelines.