Where did the peices go ?

[bigred69]

Hello all new to the sight and like all the discussions I have seen so far.I have a 1975 Mercury 500 Thunderbolt 50 Hp, the water pump impeller is shot. But where did all the pieces go? Is their something I should check before I install the new one?

 

[j_martin]

Re: Where did the peices go ?

Could have gone up into the engine and they sometimes plug up cooling passages in the engine.

Run some water through it. When you put it back in service, keep a close eye on it. You may have good water pressure and telltale, and still overheat.

The only way to be completely safe is to pull off whatever you need to to eyeball all the water passages. Usually involves pulling the power head, heads, and exhaust cover.

There's your options

hope it helps
John

 

[bigred69]

Re: Where did the peices go ?

Thanks John,

In waiting for a reply, I have found some rubber pieces in the inlet. I hope that is all of them. I took off the tube to the power head and could not see any more.
I ordered a complete pump assembly this mourning because the other one looked like it was melted a little. Better safe than sorry.

I am excited to get this boat on the water again for it has been sitting for 8 years. Pulled the carbs apart today and cleand them out. She started on the first try!!!!!!!! Will have to replace some of the wiring lots of corrosion.

I appreciat the info I hope that I don't have to dig any further into the power head.

Bigred

 

[JB]

Re: Where did the peices go ?

That is why we all recommend changing impellers before they fail, bigred.

Change every 2 yeas at the most. Better every year.

 

[bigred69]

Re: Where did the peices go ?

Thanks JB,

This is my first boat and that is good info. I used a hose hook up before I started it and notices that it was not moving water.

Can I use the hose to run the motor until the new pump arrives of course minus the impeller, and as long as water is moving?

 

[JB]

Re: Where did the peices go ?

I wouldn't, BR. Even on the muffs it is the impeller that moves the correct amount of water.

 

[bigred69]

Re: Where did the peices go ?

10-4 just eager to get the thing on the water. She's not very high hrs. mabe 30 at the most. Limited time for boating up hear and would like to get it going before it,s too cold.

Tanks
Bigred

 

[CharlieB]

Re: Where did the peices go ?

If you still have the lower unit off and waiting for your new impeller, stick that hose over the water transfer tube and turn it on. Watch the water flow out the pee hole and the exhaust, if you have a thermostat on your model remove it and (hopefully) flush any remaining particles out.

Starting the engine strictly on the hose in this manner is possible

HOWEVER..... be aware that cooling water pressure/flow is regulated by the water pump size and engine speed, over cooling can also be damaging.

It won't be that much longer to wait for your impeller/pump kit.

 

[j_martin]

Re: Where did the peices go ?

If you still have the lower unit off and waiting for your new impeller, stick that hose over the water transfer tube and turn it on. Watch the water flow out the pee hole and the exhaust, if you have a thermostat on your model remove it and (hopefully) flush any remaining particles out.

Starting the engine strictly on the hose in this manner is possible

HOWEVER..... be aware that cooling water pressure/flow is regulated by the water pump size and engine speed, over cooling can also be damaging.

It won't be that much longer to wait for your impeller/pump kit.

If you should accidentally "rap" the throttle while the engine is overcooled, you could stick a piston (cold seize) in a heartbeat.

Have patience,
John

 

[bigred69]

Re: Where did the peices go ?

I think I'll wait. I have plenty of things to do. Found 2 Hornets nests under dash complete with Hornets! Needs cleaned out. Purchased gas tank and hardware for fuel line. pump should be here in a week. Lots to do at work, probibly wo'nt get back to her for 10 days.:redface:

Great input all of you

Thanks

Bigred

 

[bigred69]

Re: Where did the peices go ?

Update!!!!!!!!!!

Shop called today said pump was in . Came home at 7 and installed pump. No water coming out tell tail, but coming out exhaust good. Ran engine for 30 min.
It never got hot.

Would it be possible to just remove the the exhaust cover plate, or should I go deeper?

Also exhaust cover never got warm at all during run! How warm should it be?

 

[j_martin]

Re: Where did the peices go ?

Tell tale has a bug nest in it, easily fixed with a coat hanger.

I don't have time to look it up, but if that engine doesn't have a thermostat, it would be normal to run cold at idle on the muffs. If it does have a t-stat, it's bad.

They get bent out of shape when you wipe out the pump rotor and overheat.

hope it helps
John

 

[bigred69]

Re: Where did the peices go ?

Thanks J Martin

Blew out tell tail was full of junk, have a good steam now.

Engine has a miss to it. Need to test the ignition.