67 40hp rudi overheating

[oldruder]

I have a 1967 evinrude model 40752 that wont stop overheating .I have changed many parts and gasket including complete waterpump kit,exhaust inner and outer gaskets,head gasket,thermostat.Ran engine with and without thermostat and cleaned all possible passages where gaskets where removed.After a very short time of running in a test tank engine starts to reach temps of 230 F and continues to clime. NOTE temp being checked with infared temp gadge. Compression steady in both cylinders at 115psi.

 

[OBJ]

Re: 67 40hp rudi overheating

First question I would ask is, "is there enough water in the test tank?". Water has to be above the pump for it to work.<br /><br />Are we certain that the impeller key didn't pop out when the impeller was installed? And, did you get both water tubes in the holes in the pump housing and the grommets didn't bend in?<br /><br />Remove the t-stat and leave the cover off. Start the motor and see if water comes out of the t-stat hole. If not, drop the lower unit connect a piece of garden hose to the inlet water tube....think the starboard pipe is the inlet. Turn the water on and see if water come out the t-stat hole. If it does, recheck the water pump. If the water dosen't flow, you may want to check the grommets at the ends of the supply water tube....means having to pull the engine block. But let's do this other stuff and see what's amiss......most likely at the pump.

 

[rdh2059]

Re: 67 40hp rudi overheating

I have one of these '67 40hp Evinrude. Overheated too. What it ended up being was pieces of an impeller that disintegrated when I ran it in a tank without enough water in it. The piece of rubber was stuck in the powerhead, blocking most of the water flow. Your sure you removed all pieces of impeller?<br /><br />Rick

 

[russeller]

Re: 67 40hp rudi overheating

you also want to keep cool water in the test take the water will get warm keep the hose in the tank while testing