1977 Merc 500 Cooling Problem

[squamlake]

I've got a 1977 Merc 500. Last year I replaced the impellor at the end of the season because the water just didn't seem to **** out very strong. First day out this year the motor would only **** water if running at a high RPM. If the motor was at a low RPM it would **** out steam from the weep hole. Is there more to the cooling system than just replacing the impellor?

 

[tashasdaddy]

Re: 1977 Merc 500 Cooling Problem

run a weed eater line up the pee hole, check for critters. i just type this for another post. read this: http://forums.iboats.com/showthread.php?t=196519

 

[squamlake]

Re: 1977 Merc 500 Cooling Problem

I will give that a try tonight. Maybe there are some critters in there. I did notice that when the water did come out of the tell tale that it was very hot.

 

[squamlake]

Re: 1977 Merc 500 Cooling Problem

Well I now know what the problem is. The impellor was totally shot. I have the lu off right now and want to replace the entire water pump. This motor has been neglected for a long time and I don't want to mess with just replacing the impellor. I was able to get the base of the water pump out and now would like to buy an entire new water pump. Where do you guys go for parts? Also, can someone show me a link where I can see the parts breakdown for the water pump and in what order they all go back together. The motor is a 1977 Merc 500 (4 cyl) with serial #4578711.

Thanks for the help!!