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72' 6 HP Yachtwin - cooling system ?

A

abl1111

Regular Contributor
I've had this old girl for about 18 years - built like a tank. I just rebuilt the water pump housing earlier in the season. When I winterize her, I use Mickey Mouse ears and that used to draw up into cooling system and cool the engine with 'tell tales' of water coming from exhaust and the 6-8 port holes would 'spit'.

When using the MM ears, the water is not flowing/ cooling properly. Water is not being drawn through the system via the MM ears; no exhaust water, no spit. However, when I use a large pail with water - then she cools and water flows properly. Note: I rebuilt the impeller/ housing for the reason, but now I know its not the impeller.

Any reason for this ?
 
The main water intake is the screen behind the propeller.----How are you dealing with water spilling out of there when using muffs ??
 
You cannot test a water pump by running on muffs. The pump is not pumping when you are doing that, only allowing hose water to pass through. It is cooling in the bucket, so relax.
 
Thx for replies. I've never liked the muffs, however, they've always been a convenient, necessary evil. I agree all is cooling as it should.

If there were better MM ears for this motor, I'd use 'em. I'm just surprised that the combination of pressure from the fresh water hose, combined with the spinning impeller, that there isn' better flow ( seems like almost none ). And, the MM ears used to work flawlessly with this motor.

Just for sh*ts and giggles - the MM ears push water in one side, the other side keeps the majority of water in the intake vicinity and the impeller wants to suck water - where is the disconnect ?
 
You could actually remove the impeller and the hose water can still flow up and through the cooling system, assuming you have sufficient hose supply. See what I mean?
 
I hear you. Perfect example - so with an impeller, you’d think water flow would surely go through the cooling system. I know I’m beating a dead horse - just curious.
Initially, when I dropped the lower unit to rr the impeller and to confirm there was no blockage in the motor, I connected a water hose to the water pickup tube and ran the motor - no blockage. Just odd that the mm ears don’t work as they should...
 
Did you find the main water intake screen behind the propeller ?-----What muffs are you using ?-----Did you try removing that rectangular plate when using the ears ?
 
MM Ears are round with water input on one side, sandwiched with cap on other side. That screens is clean - no obstruction. Rectangular plate ? I don't see anything like that. The area where the ears go is sort of small, so due to water pressure from the hose, there is blow-by.

At this point, its academic and something to make the process easier.
 
Post a picture of how / where you are using the muffs on this 1972 model 6 HP motor.----The main water intake is behind the prop.-----On that snout where the exhaust goes out.-----You can not use those muffs on that water intake.----On the side of the gear case is a rectangular plate held in with 2 screws.------4 wee holes in it.------Try removing it and use the muffs there while using duck tape on the intake screen.
 
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First - OOPS! Its a 4HP :O
I forgot.

Here's a pix of the ole girl. Next thing I want to do is remove the lower unit bearing carrier to R/R the prop bearing. Those (2) bolts holding it in place are Fro'ZEN !
 
IMG_4774.JPG

She's OLD, but works every time ! I might not get involved with the lower carrier for fear of a bolt snapping. This motor, if used at all, gets used an hour or two a season ( it's an emergency back up for when the wind dies on my 'lil sailboat )
 
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