2 hp Evinrude overheating

[magicnov]

I have a 1975 model 2502. I rebuilt the carburetor and replaced the pump (old pump was just an impellor with cover. New pump is encased in it's own housing - is this correct?). The motor starts pretty easily, but the unit seems to be overheating because when I splash water on the head it sizzles. How can I check to make sure that the water is circulating properly and that the unit is or isn't overheating. I really want to get it going so that I can take my son out fishing. Thank sfor the help.

David

 

[Xcusme]

Re: 2 hp Evinrude overheating

Welcome to iboats...

A couple of things to check. Drop the lower unit again and be sure the impeller drive key is in place. Without the key, the impeller won't turn with the driveshaft. Try forcing water up the water tube and thru the powerhead. As a last resort, remove the head and inspect the cooling passages, clean asnecessary. Replace the head gasket.
BTW, if you're testing in a barrel, be sure you have enough water to cover the pump.

 

[magicnov]

Re: 2 hp Evinrude overheating

Thanks for replying. I've checked the key and it is in place and I actually put the old impeller back in to see if it's the new unit that might be the problem (as I mentioned, the new unit is a whole assembly vs. the old impleller/cover and I'm wondering if it's pumping enough water) . Actually, I'm not even sure that the engine is running hot. I just assume that it isbecause when I splashed water on the exhaust cover on the right hand side of the motor, it sizzled. Is that a good indicator? Also, any recommendations of how to force water through the tube and head and where I should see it coming out? Really appreciate your help!

David

 

[F_R]

Re: 2 hp Evinrude overheating

The exhaust cover on that motor is not water cooled except for the forward edge. In fact, the exhaust blasts directly against the inside of the cover. So it gets hot. Likewise, the cylinder head is not water cooled right around the spark plug. The outer circumference is cooled though, absorbing heat from the center by conduction. If the other side of the block stays reasonably cool, you are good to go.

 

[magicnov]

Re: 2 hp Evinrude overheating

Thanks for the information. I'll check the temp on the other side. This is the first motor that I've worked on so I'm kind of green. Is there a visual way to see if the pump is circulating the water properly? I'm trying to figure out where the water exits and I'm assuming from the 4 small exhaust relief holes on the lower unit. If this is correct, should there be a steady stream of water exiting or a sputtering stream? Thanks again for the help.

 

[F_R]

Re: 2 hp Evinrude overheating

It's only a fine mist at those holes, and quite frankly it is not very reliable on that motor. The one I had never discharged any water out the holes at slow speed. It apparently just ran down the inside of the housing without being broken up by the exhaust so it would blow out.

 

[magicnov]

Re: 2 hp Evinrude overheating

Thanks again for the help!