Impeller – key vs pin to shaft

[johnny-infl]

and this is the skeg of the gear case that is on both the 33 and 40hp
they are identical. and that is all I know about them, they fit each other.

[fleetwin]

Oh OK, now I understand where you got the 302520 number. That number is a "casting number", not an actual part number. But yes, the skegs on the two different style gearcases are the same. Remember, that those gearcase housings are really a matched pair though, just like the two halves of OMC crankcases. The skeg can not be purchased separately, there is one part number that includes both halves of the gearcase housing.
Very interesting topic indeed…

[dan-in-tn]

Well that gives me the pictures I was looking for. Still not sure where the warm water that comes back down out of the powerhead goes before it is pumped back up? The gearcase housings are definitly different! Guess I will be doing something else. A new housing is only $125. Anybody need a RXE-13 33hp short shaft? No cover or starter, cheap.

Dan in TN

[frankr]

A 40hp (through 1972) has a dual tube, recirculating cooling system. None of the major castings nor pump are the same as a 33hp. In the 40hp, if the thermostat is closed, water returns to the pump via the second water tube. Then it is recirculated to the powerhead. This continues till the thermostat opens, and the water is discharged and replaced with fresh cool lake water. This is not an either/or situation. The thermostat constantly samples the water temp and opens or closes as necessary to maintain proper temperature.

A 33hp does not have a thermostat or water return system.

If you want to really get confused, 40hp Gale-built motors have the 33hp castings and cooling system. So do the 1973-up Johnson/Evinrudes.

[dan-in-tn]

FrankR, I understand the powerhead side of the cooling system. What I am having trouble with (haven’t taken mine apart yet, but pics are good on page #2 of this post) is where does the returning water to the pump go? I see the other hole under the pump plate, but does that just connect with the water pick up hole or what? I’m missing something here. I knew the water pump was different and the two tubes brought the water around for a second pass. Just confused as to where it goes in the gearcase casting to get back into the pump to go back up to the powerhead. Maybe it will all be clear when I tear into it, but Im trying to be ready for all repairs when I’m in there. I’m going to try and bring this boat to Suwanee. Still got to put a transom in it too. May just replace the Tee Née trailer! Thanks.

Dan in TN

[chris-p]

Yes it just mixes in with the fresh water.

There is a third system as well to make it even more complicated!

Gotta keep the t stat assembly in place on those. Exhaust gas can travel down to the water pump, rendering it useless.

[frankr]

And two versions of the "third" system.

[johnny-infl]

Jeeezzzeeee you lost me at " the neck bone is connected to the back bone "

[frankr]

quote Johnny_inFL:

Jeeezzzeeee you lost me at " the neck bone is connected to the back bone "

‘Dem bones, ‘Dem bones, ‘Dem dry bones, now hear the word of the Lord. An old spiritual song.

[johnny-infl]

well, bit the bullet and had a key slot cut into the shaft, modified the key a bit on the grinder,
and all is good !! SIXTY BUCKS ($60USD) to cut a slot !!!

so now, I will never worry about the pin wallering around in the slot !!
done done and DONE

[Author]

Posts