evinrude 40hp lark 1968 water pump trouble

[redsmufc]

Can anyone help me? I have recently rebuilt the lower unit on a 1968 evinrude 40hp lark.

I have put it all back together and i have no water being pumped out.

I have taken it apart again to check for blockages, if the 2 tubes are located properly, and if the impellor is the correct way round. all seem ok put still not working.

I have replaced all the seals in the lower unit, the grommets and the seal on the bottom of the inlet tube. and still have no joy.

It seems to be a pick up problem.... please HELP!!!!!

 

[redsmufc]

Re: evinrude 40hp lark 1968 water pump trouble

I have just been told that it could be the inlet tube seal not seated correctly, or the impellor plate not sealed.

Could this be the answer??????​

 

[R.Johnson]

Re: evinrude 40hp lark 1968 water pump trouble

If you remove the thermostat cover while running, do you have any flow at all?

 

[redsmufc]

Re: evinrude 40hp lark 1968 water pump trouble

I have check that out and there is nothing reaching that point also check tubes for blockages and they seem ok. Thanks for reply

 

[R.Johnson]

Re: evinrude 40hp lark 1968 water pump trouble

Did you put in new pump parts? Have you checked the inlet screen? On top of the pump housing there is a thick o-ring, this must be in place, is that there?

 

[redsmufc]

Re: evinrude 40hp lark 1968 water pump trouble

the inlet screen seems clear i have fitted new seals to the pump housing and new seals on the tubes, and the oring is brand new aswell..

 

[iwombat]

Re: evinrude 40hp lark 1968 water pump trouble

remove the t-stat cover and hook a hose up to the inlet tube (w/ LU off). You should get a nice unrestricted water stream when you turn the hose on.

 

[R.Johnson]

Re: evinrude 40hp lark 1968 water pump trouble

Is that an all new water pump, including the housing?

 

[redsmufc]

Re: evinrude 40hp lark 1968 water pump trouble

have done that and there is a constant flow thanks

 

[redsmufc]

Re: evinrude 40hp lark 1968 water pump trouble

hi the pump housing is not brand new although it looks fairly new. i did re seal it though.

 

[iwombat]

Re: evinrude 40hp lark 1968 water pump trouble

Well, that removes a blockage from the list.

Maybe you should describe your set-up for testing this motor. Muffs or barrel. If barrel how high is the water on the midsection?

 

[R.Johnson]

Re: evinrude 40hp lark 1968 water pump trouble

If every thing is as you discribe, I am lost as to where the problem is. As the other post ask's how are you testing?

 

[redsmufc]

Re: evinrude 40hp lark 1968 water pump trouble

i have been testing this in a barrel i filled it to about 4" above the water pump housing level..

is there anyway of testing the pump is picking up without the lu being connected to the main unit??

also should i try re sealing the impellor plate??

or is there a special way of installing the seal on the lower part of the inlet tube???

 

[R.Johnson]

Re: evinrude 40hp lark 1968 water pump trouble

Not only seal the plate down, look at the walls' of the cavity under the plate, and see if there are any cracks', or breaks'.

 

[redsmufc]

Re: evinrude 40hp lark 1968 water pump trouble

i don't think its cracked but i'll double check tomorrow to make sure. Its starting to baffle me

many thanks for your help!!!!!!

 

[Evinrude Boater]

Re: evinrude 40hp lark 1968 water pump trouble

Mine is cracked. I hope that isn't a problem for pumping water. As I understand it can allow exhaust gases into the water and heat things up.

 

[redsmufc]

Re: evinrude 40hp lark 1968 water pump trouble

im hoping its something i've done maybe not sealed properly i hope lol

 

[Evinrude Boater]

Re: evinrude 40hp lark 1968 water pump trouble

The drive shaft is 5/8" diameter so if you have a 3/4" chuck you can spin it in a barrel and see what happens.

 

[redsmufc]

Re: evinrude 40hp lark 1968 water pump trouble

many thanks ill give it a go

 

[HighTrim]

Re: evinrude 40hp lark 1968 water pump trouble

I assume you remembered the impeller key right?