No water out transom or exhaust

toolman4

Petty Officer 2nd Class
Joined
Apr 1, 2010
Messages
128
Understood...good explanations. Should have the kit by thursday.
 

tank1949

Lieutenant Commander
Joined
Apr 4, 2013
Messages
1,883
Have a 1999 mecrusier 4.3 alpha one . I had the muffs on to do a preseason check and have water up to the manifold on top but nothing out the exhausts. When I squeeze the big hose from the water pump to the manifold on top of motor I here water but nothing is going to the risers. Can it air lock...how long can you run without impeller damage?
I suspect something malfunctioning in water pickup. However, perhaps this has been discussed, but is boat salt water used/stored? It is my understanding that fresh water boat risers and exhaust manifolds don't clog up with rusts as frequent as salt water ones do. I have replaced several salt water manifolds/risers over my lifetime. Before you tear apart everything, with motor not running, you might want to disconnect plumbing at riser/manifold and hand connect a garden hose and see if there is any restrictions. If there is, you will get spray back in your face. I also had to replace water passage tube/seals in an Alpha one time and notice that there was too much corrosion to make a good seal. If my old memory serves me correctly, I had to replace upper unit. Good luck!
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
.... I also had to replace water passage tube/seals in an Alpha one time and notice that there was too much corrosion to make a good seal. If my old memory serves me correctly, I had to replace upper unit. Good luck!
For the Alpha One yes, the water pocket cover was a problem area. But OP has a 1999, that makes it a Gen II, no water pocket covers in Gen IIs...
 

poconojoe

Lieutenant Commander
Joined
Sep 10, 2010
Messages
1,966
Correct me if I'm wrong, but if the impeller is installed with the veins backward, it won't pump properly.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Correct me if I'm wrong, but if the impeller is installed with the veins backward, it won't pump properly.
Consider yourself corrected... When you stop an engine, often as it comes to rest it gives a 'kick' the other way. That's enough to flick some or all of the blades the other way. The next time the engine is started, they flick back to other way...

Chris.
 

poconojoe

Lieutenant Commander
Joined
Sep 10, 2010
Messages
1,966
Consider yourself corrected... When you stop an engine, often as it comes to rest it gives a 'kick' the other way. That's enough to flick some or all of the blades the other way. The next time the engine is started, they flick back to other way...

Chris.
Interesting.
I thought I remember reading somewhere to be careful that it was install in the right direction.

I thought I'd suggest that because sometimes the simple answers are not thought of...

I stand corrected.
 

toolman4

Petty Officer 2nd Class
Joined
Apr 1, 2010
Messages
128
Finally got the impeller installed and that fixed my problem. It took 1 minute for the water to come out the back of the transom at idle. Is that too long? How long can you actually wait for water out the back with the muffs on before hurting anything? I had good water pressure and a little water was still coming out the muffs at idle.
 

ImTheBiggerBoat

Seaman Apprentice
Joined
May 4, 2021
Messages
33
Appreciate the help...got the impeller kit coming. Is it odd with even the muff pressure no water was getting up to thermostat housing with an impeller and housing that looks perfect? How do I know if my circulating pump is working correctly with that water sitting in the hose above it?
the impeller acts like a vacuum, unless it's spinning and forcing water past it and through the system, it will act like a closed door.
 
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