1974 Evinrude Sizzler Overheating

[Sizzler74]

Recently I acquired a 1974 Evinrude Sizzler from a barn where it sat for the last 15 years. I ran it on the Fox River and found out it overheats.
All tests I did are preformed in a test tank.
The motor has no tell tale.
This is what I have tried so far:
#1 Replaced the water pump impeller and gaskets, even thought original impeller looked new.
#2 Replaced the thermostat. Old one was full of sand.
Ran motor with thermostat removed. Steady stream of water came out of the hole where the thermostat normally is.
Reinstalled the cylinder head cover and the motor still overheats.
Removed the lower unit and hooked a hose to the water tube. With engine not running water pours out of the cavity above the water tube. No water flows out of the exhaust ports. Water also pours out around the lower exhaust housing mounts on the outside. Is this normal?
Any help would be great!

 

[Will Bark]

Re: 1974 Evinrude Sizzler Overheating

Sounds like the water tube is not seated in the grommet at the power head however; wait for the gurus to chime in and they can tell you what to look for and how to proceed with a fix. Good luck

 

[Bosunsmate]

Re: 1974 Evinrude Sizzler Overheating

If u havent try running it while on the hose that way you narrow it down to waterpump or engine.
Sounds to me like its coming out where it should

 

[boobie]

Re: 1974 Evinrude Sizzler Overheating

How did you determine it was over heating ?? Hot horn, temp gun or what ??

 

[Sizzler74]

Re: 1974 Evinrude Sizzler Overheating

How did you determine it was over heating ?? Hot horn, temp gun or what ??

Temp gun said the top of the block was 230 F when I shut it down. Horn temp was going off also.

 

[Sizzler74]

Re: 1974 Evinrude Sizzler Overheating

If u havent try running it while on the hose that way you narrow it down to waterpump or engine.
Sounds to me like its coming out where it should

Is there supposed to be a hole that's been drilled in the water tube?

 

[racerone]

Re: 1974 Evinrude Sizzler Overheating

Some motors have a tiny hole drilled in the water tube.--------Do a compression test. A blown head gasket can cause overheat.

 

[boobie]

Re: 1974 Evinrude Sizzler Overheating

Agree +1 with the compression check......

 

[oldboat1]

Re: 1974 Evinrude Sizzler Overheating

sand in the t.stat housing? It must have gotten sucked up there, and would likely be somewhere else in the water jacket. I like the idea of forcing water up through the water tube after removing the lower unit -- have always thought that is a good back flush when I had motors that had difficult heating issues. In doing that, though, I sometimes did it with the head cover removed to make sure the water was getting up into the water jacket channels. I would think that there could be some sand up in there.

 

[oldboat1]

Re: 1974 Evinrude Sizzler Overheating

just struck me that the sand you found could be the remnants of a mud wasp nest or two, given that the motor was a barn find. Sand is sand, I guess, but it would be good to see if there is part of a nest still in there somewhere -- maybe in the housing around water intake areas in the gear case, or up in the leg under the powerhead. Water exhausts in the opening at the rear of the leg, and that is also a spot for a nest and blockage.

 

[bonz_d]

Re: 1974 Evinrude Sizzler Overheating

Fox River! Where about?

What size engine is this? 50hp. 75hp?

 

[TN-25]

Re: 1974 Evinrude Sizzler Overheating

Am I the only person here that sees the irony of the overheating motor being a "Sizzler"?



The 50 Sizzler was available in North America for 1974 & 1975.