1968 evinrude water pump problems

redsmufc

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Sep 30, 2007
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Hi i have a 1968 40hp evinrude lark serial no.rds-30d. I have recently change all the seals in the lower unit and water pump housings etc. the only thing i have not changed is the water pump housing. i have put it back together and it is not pumping water checked all the impellor and the obvious any idea on what it could be. :confused:
 

skimmer

Petty Officer 2nd Class
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Aug 2, 2007
Messages
186
Re: 1968 evinrude water pump problems

Check for blockage in the water tube, under the exhaust cover, thermostat, and water jacket.
 

F_R

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Jul 7, 2006
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Re: 1968 evinrude water pump problems

Did it work before you took it apart?

Are you running it on a boat in the lake or in a bucket?

Have you messed with anything else? (Thermostat)

Are you sure you got both water tubes entered into the grommets?

Are you sure the water tubes are on the correct sides? (one side often has a hole to cool the shift wire) Won't work if reversed.
 

redsmufc

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Sep 30, 2007
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Re: 1968 evinrude water pump problems

hi

yes it did work before, i am running it up in a 4ft deep wheelie bin, and no i have not touched the thermostat and the tubes are in the correct way round. Starting to think there is a blockage.
 

redsmufc

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Re: 1968 evinrude water pump problems

can you tell me where the thermostat is housed??? thanks
 

F_R

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Re: 1968 evinrude water pump problems

A blockage would be the last thing I would suspect, since it worked before.... Unless the blockage was somehow induced by you when you took it apart. The 'stat is on top of the cylinder head, under the little triangular cover. DON'T remove the plastic housing and relief valve from in there, or you'll be back here again trying to figure out two problems.
 

BoatBuoy

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May 29, 2004
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Re: 1968 evinrude water pump problems

Even if it's in a 4ft bin, the water must come up above the level of the water pump.
 

redsmufc

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Sep 30, 2007
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Re: 1968 evinrude water pump problems

yes it does cover the water pump housing. but i may have caused this problem myself by using sealant on the impellor plate that sits underneath the impellor. would that cause it? not used anywhere else. also i dont beleive the lower part is blocked
 

F_R

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28,226
Re: 1968 evinrude water pump problems

You are supposed to use sealant UNDER the plate. None is required above it.
 

redsmufc

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Sep 30, 2007
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Re: 1968 evinrude water pump problems

many thanks for your help i will start stripping it again tommorow
 

jay_merrill

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Joined
Dec 5, 2007
Messages
5,653
Re: 1968 evinrude water pump problems

This may seem dumb but ... did you put the impeller in the right way? Its very easy to get the "bend" in the blades backwards if you don't do it correctly.
 
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