Mariner 5M no impeller?

[guy48065]

I have a Mariner 5M model 661S serial 035994. Some lookups don't even accept 6-digit serials for Mariner outboards but as near as I can figure this is a 1976 5 HP made by Yamaha. It has an air shroud under the cowl and some exposed cylinder fins sticking through the lower cowl so the power head is air cooled. I can't find an impeller on any parts diagram so is the lower leg also air-cooled or is the little pipe that faces the prop all there is to feed water into the lower? How does this cool when not in gear?

 

[roscoe]

What cools the gearcase on other outboards?

Feeding water into a gearcase would get expensive.

At a loss.

 

[boscoe99]

Water flowing over the lower unit is the cooling mechanism.

 

[racerone]

?----Some use a wee pipe to push water up to cool the EXHAUST coming out of the aircooled motor.-----Saves burning the paint off them.