help help please, evinrude bigtwin 40hp impeller

[chestercheese]

hello you good people
please can someone help me with a proplem?
i've got an evinrude bigtwin 40hp about 1964 ish,
i've done coils points etc, run sweat, starts up first time everytime,
it was'nt pumping water, so done new impeller, started it up, pumps water great, head nice and cool, left it running for about 15min, then switched it off to put the rest of the cover back on, started it up again to find the flow of water was'nt great and the head was getting very hot (not boiling) i had more steam coming out of the tell tell than water, and the water was very hot to, could someone please help me and tell me what i've done wrong???
i had a look at the top of the engine to find (what i think should be the themostate) but there was'nt anything in there, just some sort of pressure valve on a spring, which seems to be working fine,
please please could someone help me, i've done to much to this engine just to give up on it now,
many many thanks dan

 

[tx1961whaler]

Re: help help please, evinrude bigtwin 40hp impeller

Put more water in the barrel ?
Te water level has to be quite high for the pump to work

 

[chestercheese]

Re: help help please, evinrude bigtwin 40hp impeller

hello, i had the hole bottom end in the water, well above all the intakes, how high up should the water level be? thanks dan

 

[a70eliminator]

Re: help help please, evinrude bigtwin 40hp impeller

Did you add the tell tale? those old motors don't have tell tales. The water spits out mixed with exhaust, running in a test barrel isn't design, you'll be surprised at the difference another foot of water will make, I did add a tell tale to my engine and I get a much stronger stream when the the boat is actually in the lake motor sitting deep, then when on plane the sheer force of the water does most the work.
Here's a couple common mistakes made,
The half moon key pushed out of place and droped down into the housing while you were sliding the impeller into place.
Or the wipers were oriented in the wrong direction when placed into the housing.
Or debris from the disintigrated impeller found it's way up the watertube and into the adapter plate restricting water supply.

 

[chestercheese]

Re: help help please, evinrude bigtwin 40hp impeller

hello,
i had loads of water the first time i started, (with new impeller) the head was lovely and cool, but when i turn'd it off and left for 15mins or so? i started it up and the water flow (out of the exhaust) was more steam and not so much water, and the head was getting hot, i did have alot of water in the tank, it was prob upto half of the leg? i cant think of anything i've done wrong? someone before me has taken out the thermostat, would this cause the spring valve to stay closed? so that the water would bypass the head and go stright out the exhaust? could it have been stuck open the first time, (when running lovely) then stuck closed when i re-started? the valve moves ok now,
how would i check the adapter plate for blockage? and where is that?
many many thanks dan

 

[glassmaster68]

Re: help help please, evinrude bigtwin 40hp impeller

i have a 66 lark 8 40hp,,,,,the manual says there is tattletale flow of water from the idle relief in the exhaust housing,,,and my engine has one also out of the small holes,,,,i just had my impeller replaced,,i have no flow also,but i dont think there is supposed to be a flow from these motors,,more like alot of spitting out of the small holes,warm water after engine is warmed up,,,,its supposed to take about 30 sec ,,,i didnt let mine run that long yet,,,was kindof afraid