New impeller still no water?

[Danny Shelter]

Hi guys, I got a brown band mercury 50hp and it wasn't pumping water,it would run for a few seconds and knock off so I changed the impeller thinking it was an overheating knock off and this would solve it but no surprise nothing changed, if anyone has any ideas i would l appreciate reading them,
cheers, Dan.

 

[Lincoln253]

Have u checked to see if u sucked something into the pickup that is blocking the flow.

 

[Chris1956]

It takes 30 seconds or so to show water at the telltale. If your motor only runs a few seconds, that sounds like carb or ign issues. The motor would not turn itself off after a few seconds for any reason.

 

[Lincoln253]

Have u tried running it on carb cleaner.... I just had a boat this week in our shop that sat with fuel for 2 years and luckily was able to run it on carb cleaner long enough to clear itself out and run fine.... That was the kicker unfortunately the yamaha 150 on it had to have a complete fuel system overhaul..... Sometimes u can get lucky. I can think of 20 things I would have tried before the impeller on a non runner.... Chris is right U have something else goIn on that's either fuel or ignition related or even electrical for that matter

 

[Chris1956]

Running on carb cleaner is a real bad idea. First of all it is not gasoline, and secondly it has no oil in it. It is better to figure out what is wrong and fix it the right way.