1996 35 evinrude stops pumping water

[Wayne MacDonald]

I have a 1996 2 stroke Evinrude 35 hp, 3 cylinder outboard (35KLEDS). Last year it overheated badly melting the oil injection tank and some hoses. The water pump, oil tank and melted hoses were replaced and all seemed fine. Upon starting it in the water tank in the yard this spring it seemed to be running just fine. Water was pumping great out of the tell tale hole in the back. After about 5 minutes the tell tale started to die and then quit. The tell tale then started to steam so I shut it down, pulled the pump and thermostat, all were ok. I restarted and the results were repeated. After letting the engine cool over night I repeated the start up and used a faster idle, same result but sooner. I would really like a copy of the water flow diagram for this unit so I can trouble shoot further. I am guessing now that I may have a head leak (the compression is an even 120 psig on all cylinders) or an exhaust plate burn through if there is such a thing on this unit (always a problem with the 1955 3hp units) Any suggestions

 

[kenmyfam]

Re: 1996 35 evinrude stops pumping water

OK so what caused the original overheat that melted stuff ??
Let's go from there.

 

[Wayne MacDonald]

Re: 1996 35 evinrude stops pumping water

the water pump had destructed, proabably due to a plastic bag in the ocean. I have blown air through all the passages . first i blew air up the cast in place water tube, air came freely out the tell tale and the thermosts (removed), then i blocked the thermostats opening with a stopper with an air opening and pushed air back to the tell tale and the leg tube hoding the opening at the pump end of the cast in place tube closed. when i do both these exercises i hear a lot of air entering the leg housing. without a flow diagram and without removing the power head from the upper leg i can not tell if there is a way air (water) is supposed to flow to the leg or if i have a hole in the casting.

 

[kenmyfam]

Re: 1996 35 evinrude stops pumping water

You may well still have a piece of old impeller in there somewhere. Did you flush it both ways (directions) ??

 

[Wayne MacDonald]

Re: 1996 35 evinrude stops pumping water

yes i have flushed from the tell tale both ways and from the thermostat both ways. with a hose into the thermostat and back to the pump i have a good flow and whem I block the pump end i boild up pressure in the pump tube so i have now convinced myself that everything above the pump is fine. i wll try another impeller and see what happens

 

[Wayne MacDonald]

Re: 1996 35 evinrude stops pumping water

I have had a second thought re my problem( its a holiday today and i can not get another impeller. the overheating may have caused a head o ring to fail which lets cylinder pressur gas into the cooling water. my compression tests are ok but a small leakmay not show up during the compression test which i have done with about 10 engine cycles. i can not be at the guage and the starter at the same time.

 

[Billy O]

Re: 1996 35 evinrude stops pumping water

Stupid question! When you put pump housing back on did you turn drive shaft in clock wise direction? Had to ask cause I don't know if you're new at this or not. If so then you did it correctly. What type of key does it have for holding impeller?

 

[Wayne MacDonald]

Re: 1996 35 evinrude stops pumping water

the impeller was installed properly with the odd shaped plastic key

Good news or maybe.
as a last ditch attempt i started the engine with the whole thermostat assembly removed, a great burst of water and now the dam thing is pumping water. this is after many flushes and high pressure air blows. i did not find or notice anything in the water which blew out of the thermostat but it now works. ran it for 15 min and it still works

thanks to all for your questions and suggestions