water tail and water pump

[jdcoombs]

I'm VERY new to boating. I have a 1969 Evinrude 40 HP. Got it running w/ a carb rebuild, but when testing in barrel, don't know if the water pump works.
Intake is the little screen, I presume, but should the end of that tube be plugged? Looks like water can flow right past.
Where does the water come out? Is it the larger hole near top? Is there some way to hook a hose to the intake to run the engine a while?

Thanks.
In a quandry

 

[HighTrim]

Re: water tail and water pump

You can test your motor in your driveway in 1 of 2 ways. You can submerge the lu in a garbage can or barrel cut in half full of water, or you can get "muffs" to hook up to the water intake that you hook up with a garden hose. The only problem is im unsure of how deep the water line will have to be for you, or if you can even use muffs at all. I dont think your water pump will "suck" the water up, it has to be lower than the water line to function properly, so you must make sure of this. Also never run your motor past 1500 rpm while testing, and only for short periods, youll end up with bigger problems than you started with. GL

 

[Molaker]

Re: water tail and water pump

HighTrim, I don't think a '69 40hp can use regular "muffs". I know my '71 40hp cannot because of the main water pick-up configuration. I just use a large trash can and make sure the water level is well above the lower unit.

 

[HighTrim]

Re: water tail and water pump

Thats what I thought and was hesitant to even mention the muffs and wanted him to make sure about his type of cooling system b4 proceeding. Just searching , make sure that the first buldge above the cavitation plate is well submerged.Ty Molaker for clarifying.

 

[jdcoombs]

Re: water tail and water pump

Thanks for the replies.
Muffs definitely don't work. I have a screen about 1.25 hinches high, and .5 inches wide, facing forward.
A was able to get it submerged only to the lower hinge, about 10" below the cooling water exit, maybe 14" qbove the prop. I got a spray out the back. Not a "flow". Will that be sufficient? I'm getting ready to take it to the lake for a trial. How will I know if it's cooling sufficiently?
Still confused

 

[Molaker]

Re: water tail and water pump

A spray is about all I get from my '71. Not only is the main water pick-up under water, so is the main exhaust. But, there's nothing like a good dip in the lake to verify the cooling system. After running it a bit in the lake (2-3 minutes), if it is cooling properly you should be able to touch the head without burning your finger or even being very uncomfortable.

 

[F_R]

Re: water tail and water pump

That motor has a thermostat controlled recirculating cooling system. When the 'stat is closed, water is directed back to the water pump for recirculation. During that mode, a little bit of water still will spray out the back. Once normal operating temp is reached, the 'stat opens and the recirculation ends and there will be a heavier spray out the back but most of the water is discharged with the underwater exhaust.

During normal operation the thermostat will open and close as often as needed to maintain the right temperature. It will be in recirculation mode (light spray) most of the time at idle. Unless your lake is as hot as it is here.

 

[clemsonfor]

Re: water tail and water pump

No one has positivily answered this question, yet, no you cant use muffs on that motor, there is a plate avove the cavitation plate but that is not a water pickup. You are correct in the water pickup location, normal muffs obviously dont work, there use to be a manufacturer (tempo, i think) that made a device to slip over the screen to use your hose (faterinlaws dads old boat had one in it) but id rater use a trash can, because i used it once on his and it seems like it could easily slip off. I have a 70' 25hp that is the same as yours, cant use muffs. Yes the end of the tube is open and exhaust water is directed out it does not suck out of there. Also exaust and spray comes out of the holes direcly under the cowl on the back of the LU and at idle is just a spray and at Wide open is more like a flow!

-Nate

 

[jdcoombs]

Re: water tail and water pump

Thanks Y'all. Seems the WP works. A dunk in the lake helped. I'll plan on replacing it and the thermostat this winter.