Marnier 135 water pump issues/questions

[cdlong]

Rebuilt both water pumps today. New gaskets, top housing & impellers. My neighbor didn't have his "run tank", so I'm using the muffs with city water pressure which I guess to be 60 psi.. The port side engine has a steady stream, the spits, then steady stream then spit. Blew air into the tattle tail and no blockage that I could tell. Engine RPMs were 1000.
Starboard engine is the problem. No water at all. Blew through the tattle tail and no blockage. Ran again, no water. Removed the water hose from the top right cylinder head. Couldn't get water to go into the fitting on the right head. No problem getting air in. Put the city water hose on the coolant hose from the right head to the left head, water flowed into it. Dropped the lower unit again. Had to force the long tube from the power head to the water pump out. Bent the crap out of it.Water pump housing, impeller were good, top gasket between water pump top & bottom was ripped. Replaced gasket and reassembled water pump. Turned water on. Very little flow out the water pump discharge port. I have a lot of water coming out around the muffs.
Any ideas where my issue is? Won't get on the water tomorrow.
1st picture-water pump installed. 2nd picture-flow from muffs. 3rd picture-city water is on full.

[bobbert]

Looks like blockage between the holes in the lower unit and the bottom of the pump housing. Remove pump again and check. If not clear, you know cleanit up.
Had the same problem last fall caused by barnicles, and sea worms. After clean up get some outdrive anit fouling into the passage. Don't forget to check the holes in the lower.
Check to make sure nothing is reversed. Good Luck

[JohnC]

Maybe a dumb question but is the impeller twisted/turning in the right direction? I only ask because I almost installed one the wrong direction (counter-rotating motor shafts turn the same way as the standard). I caught my mental flatulation before I assembled it but its an easy mistake.

[cdlong]

I didn't know you could install impellers wrong. Wouldn't the driveshaft turning cause the impeller to twist the correct way? How would I know which direction the fins/blades should be curved?

[JohnC]

I am not familiar with Mariner. On my Yamaha the impeller blades are pretty stiff and larger diameter than the pump housing; I don't think there is enough room for the blades to flip around as the shaft rotates. If that is not the case with your Mariner then sorry for the confusion. I lube the housing with a little grease on my finger and twist the impeller in the correct direction when I put it in. The shaft turns clockwise, you can look at the good motor running to confirm direction of rotation.

I did a quick search and found this. Good luck!
https://www.youtube.com/watch?v=OuilMAOMpgQ

[GameOnSalmon]

Cdlong.... Please Check Your PM's.
Thanks Robert

[bobbert]

Yes, impeller can be installed with the vanes "bent" the wrong way and not pump.
You have to turn the shaft as you push down the upper pump housing.
The vanes can also flip if the engine hiccups.

[cdlong]

Yes, you were correct. Impeller was installed wrong. Water cavity to water pump is clear, no blockage. Ordered new water tube. I need to check port side. Do you know if water tube should stay up or drop with lower unit?

[JohnC]

I don't know for sure, it's best to look up the service manual and follow it when in doubt. I am not a mechanic but I have done a few different motors and they have always had the water tube already in the power head when reinstalling the lower unit. There should be a rubber sleeve of some kind to seal the bottom of the water tube where it connects to the pump housing, that is usually the last thing to go together as you raise the lower unit into position.
The length of the parts is staggered so that they can be aligned one at a time when reinstalling the lower unit. The shaft (first), shifting rod (second) and water tube (third) all have to be aligned as you raise it into position.

[Fr. Frank]

On a Mercury/Mariner, it's better to put the plastic sleeve into the pump housing and raise it up onto the tube in the midsection. There should be a foam gasket/o-ring in the housing into which the plastic sleeve fits semi-snugly.