Mercruiser 3.0 water pump will not turn,

[Stephen12345]

Today I took the boat out on the water for the first time ( Sea Ray 170) in 7 or so years. The boat ran grand but was running a little hot and would then cool down a bit and seemed fine. I had the boat under full acceleration and then it just died and cut power ( i found the problem for that was the connector fell off the coil... This one some hours later i fixed this problem). On the water the boat was turning over find but would not start ( cause of the lose connection) but the gauge was than jump from 140 degrees to say 170 3/4 towards the top). I took the boat out of the water and left it in the shed and a few hours later i came back and reconnected the wirer and it fired and ran but i turned it off straight away as i noticed the water pump was not turning, ( could this have been caused cause the impeller was worn and then cause the water pump to over heat and sized ( when less turning before this it was turning fine), Ive order a new water pump, impeller and thermostat to be safe. Should this solve the problem?, Ive only ordered the impeller with out realising i need other parts too, like the gaskets etc, Should i order them too or will i get away with already is there and just change the impeller, Any advice would be much appreciated.

Stephen

 

[Scott Danforth]

welcome aboard

sitting for 7 years would have roached the raw water impeller

it could have also had bad water pump seals. then when you ran it, that roached your circulating pump

hope you ran it on muffs and didnt fire it up without muffs

I would get a complete raw water pump assembly including the housing, etc.

you should do a complete stem to stern maintenance event, including the trailer.

 

[Stephen12345]

Thank you very much for the reply,

I ran it with muffs and then ran it out in the water, Im going to put a new pump and thermostat on it tomorrow and see if the temperature stays level... In any note the water pump id say is the original from 1991 so its time for a change, Ill run it with a new thermostat and water pump and see how it goes, Ill do the impeller next month when we are heading into the winter, Of course if i see it rise about the half way mark with the new thermostat and water pump I will turn it off and do the impeller straight away, We just need the boat to go out 2 more days and we will get this job done,

 

[Scott Danforth]

you need to do the impeller first. the impeller is rubber and they last a maximum of about 5 years. your bellows are also rubber and you should pull the drive and inspect them as well.

this is part of the stem to stern maintenance that needs to be done prior to using the boat. especially if the boat has been sitting for 7 years.

 

[Burning$]

Does the impeller and housing create a vacuum to pull water in from the vents below? Just wondering if don’t have a good seal if that would be a major issue on water flow?