1989 5.7 260hp water movement

[JWhit]

I have looked through the service manual but not 100% sure how the water moves through the system. I just got the motor running (after sitting for many years) and am wondering if water should be pulled in at idle? ran for about 10 seconds in a large tub of water and did not see any agitation, so shut off. Planning on impeller replacement, but wondering what other things to look for to make sure water is moving? thanks for any advice on how it moves water normally or what should be replaced/checked

 

[NateZ]

Re: 1989 5.7 260hp water movement

High temps is one indication there is no water.

Put your hand on the water intake inside the tub and see if there is suction. Or run it with ear muffs that way you will be able to see the water comming out.

Nate

 

[FreeBeeTony]

Re: 1989 5.7 260hp water movement

Maybe it has an engine mounted raw water pump and has a thru hull water pick-up.....

 

[JWhit]

Re: 1989 5.7 260hp water movement

Well I pulled the lower unit off the drive, and the impeller was in many pieces with no fins left at all. Clearly need to replace that and seals, casing looks good. Is there another impeller on the motor that I should replace as well? Seems to look like the exact same part number? Thanks

 

[John_S]

Re: 1989 5.7 260hp water movement

Make sure you find all the pieces of the impeller. Back flush the line if you don't have them all. Those peices will cause you all sorts of grief depending on where the lodge.

Sounds like an alpha, so along with the drive pump, you only have the engine circulation pump.

 

[JWhit]

Re: 1989 5.7 260hp water movement

Yes it is an alpha drive, does the circulation pump have an impeller that I should try to change as well? Found an upper water pump kit on here but not sure that is correct. Thanks for the advice, will flush soon

 

[John_S]

Re: 1989 5.7 260hp water movement

The engine water circ pump is like the same as on car, except has components that will not rust. It does not have any rubber impeller. Unless, some pieces got up that far.
I wouldn't mess with that yet.

Find the missing pieces, and do a retest.

BTW water should spray out the exhaust reliefs, within a minute of start-up, sooner if engine is full of water. Very little goes out the exhaust/prop to agitate the water in tub. Keep a hose running into the tub, while you are running the engine.

 

[JWhit]

Re: 1989 5.7 260hp water movement

thanks for the info, I did have the hose running to the tub just in case, and will retest with impeller fixed. thanks for the exhaust info as well, assumed it came out the main pipes and not prop on this one

i have the ear muffs also so I'll test with both as soon as parts come in and follow up

 

[JWhit]

Re: 1989 5.7 260hp water movement

Put in new impeller, new oil, eventually got back together with shifting working. With muffs I was successful getting water out of the exhaust, although my lower hose to the t-stat is leaking and will be replaced as soon as it arrives. also flushed the line and confirmed rubber chunks were all in the outdrive. Thanks for all the help, hopefully will be fully functional soon!