Need to Replace Water impeller on 190 OMC

T

Tswany

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Jan 25, 2007
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How hard is it to replace the impeller on a 1977 190 OMC? I have never done it before and am thinking about doing it myself. Any advice?
 
Boomyal

Boomyal

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Re: Need to Replace Water impeller on 190 OMC

How do you know you need to replace it? Is the boat a freshwater or saltwater boat?

I would get a manual first. The outdrive needs to come off, which is pretty easy for your electric shift and you'll want to be careful when removing any bolts. If you get undue resistance, ask for advice before snapping them off.

Chase all your bolt holes with a tap, blow them out and grease up the bolt threads before reinstalling.

Those are just general bits. Get the manual before you start. A Seloc should do even tho they are not the best manuals. The job is not that difficult but a bit perplexing if you have not done one before.
 
T

Tswany

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Re: Need to Replace Water impeller on 190 OMC

Its a freshwater boat, it was running hot, it just got a new (used) outdrive and this was the first time running it. I took off the hose coming into the thermostat housing from the outdrive and no water would come through it unless i put the garden hose right against the intake, forceing it through.
 
T

Tswany

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Re: Need to Replace Water impeller on 190 OMC

I do have a manual already.
 
Boomyal

Boomyal

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Re: Need to Replace Water impeller on 190 OMC

Tswany said:
Its a freshwater boat, it was running hot, it just got a new (used) outdrive and this was the first time running it. I took off the hose coming into the thermostat housing from the outdrive and no water would come through it unless i put the garden hose right against the intake, forceing it through.
Click to expand...

I'm not quite understanding your diagnostic proceedure. Are you on muffs? Just putting a hose up against the intakes is not going to tell the story.

Have you pulled the hose from the outdrive while you are sitting in the water?

Hate to see you go thru it all just to find out you've got a bad thermostat. Those OMC impellers are pretty big and they do not need to be changed as frequently as the dinky little Merc impellers do.
 
T

Tswany

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Re: Need to Replace Water impeller on 190 OMC

No muffs, at first i had the lower unit in submerged in a bucket of water, removed the hose, started it, and no water came out. Then i raised the lower unit, disconnected the coil so the boat wouldnt start, and put the garden hose right against the intake (with the screen taken off) and water came through. I havent launched it again yet, but i am planning on trying that tonight. This is a 1977 OMC so there is just the one intake right above the prop.
 
KaGee

KaGee

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Re: Need to Replace Water impeller on 190 OMC

just got a new (used) outdrive and this was the first time running it.
Click to expand...

Should have replaced the impeller from the get go.

As Boomer alluded too, the job gets very hard if the bolts won't come out. That's your main concern IMO. You have to separate the drive to get to the waterpump. Just take your time, use plenty of heat and PB Blaster on the bolts.
 
T

Tswany

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Re: Need to Replace Water impeller on 190 OMC

Alright, thanks for the help.
 
Boomyal

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