Will not pee

scully81152

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Sep 16, 2024
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Changed water pump, still no pee, thermostat is good, opened thermostat housing and started engine with no water at thermostat and running engine with muffs...always cleaned engine before with muffs and no problem until now. 2017 Yamaha 115 xb
 

99yam40

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drop it into the water and try it, sometimes they have trouble on a hose.

did you use a Yamaha water pump kit or after market?
 

99yam40

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why was it replaced?
did you have a overheat problem?
if the housing has a problem it needs to replaced also
 

scully81152

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After fishing, brought home and as usual, every time, I ran salt away to clean engine.
But this time no peeing and alarm rang, so after reading many articles, I changed the water pump impellar and parts that came with the kit but not the white housing. 100hrs on engine so figured it was time.
 

mike_i

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Jun 28, 2017
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942
What condition was the old impeller in? Was it missing any chunks of rubber? Can you run the motor in a tank or trash can, making sure the water level is above the water pump level? Try shoving a piece of wire up the pisser hole.
 

airshot

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Flush it or blow air thru the pee tube, probably blocked, not unusual.
 

airshot

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I thought the same thing, but he said he was not getting water to the stat, so blocked tell tail would not cause that
Then chase that back, could be blocked in a variety of places, just gotta jeep tracing it back to be sure all us clear.
 

99yam40

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Then chase that back, could be blocked in a variety of places, just gotta jeep tracing it back to be sure all us clear.
exactly what would block the water from coming out of the stat opening with it out?

if water does not get up to the top of the head/block it is ot pumping properly
 

scully81152

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I thought the old impeller looked good. Yesterday I put the engine in a tub up to the cavitation plate and no success. May get a higher one, just above the other outlets and try shooting water down the thermostat housing. I see from a Crowley marine diagram that there is a pressure control valve. Would that stop water? I followed the pee hole hose to a brass nipple and when the motor was running air was coming out of that and also the hose when I reconnected it so no blockage there. Thanks to all for the help.
 

cyclops222

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Mar 21, 2024
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Water MUST MUST be way above the Cavitation Plate. I would use 8 to 10" above it. Did you accidently trim the motor up too high ?
The impellor may be slightly worn if run long enough. You may have been sold the wrong impellor.
 

99yam40

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I thought the old impeller looked good. Yesterday I put the engine in a tub up to the cavitation plate and no success. May get a higher one, just above the other outlets and try shooting water down the thermostat housing. I see from a Crowley marine diagram that there is a pressure control valve. Would that stop water? I followed the pee hole hose to a brass nipple and when the motor was running air was coming out of that and also the hose when I reconnected it so no blockage there. Thanks to all for the help.
if the PRV is stuck open it will dump too much water to fill the block at low RPM
 

scully81152

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If water must be above cavitation plate, why does the muffs usually work? Anyway I will try a larger bucket.
And what would happen if this PRV is stuck closed?
I am so confused
 

99yam40

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If water must be above cavitation plate, why does the muffs usually work? Anyway I will try a larger bucket.
And what would happen if this PRV is stuck closed?
I am so confused
why worry about that.
check to see if it is stuck open

I just reread your other post, I have no idea how air would be coming out of the pisser, maybe it is exhaust gases from a blown head gasket letting exhaust into the cooling passages
 
Last edited:

airshot

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Jul 22, 2008
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Muffs work because it’s got pressure from the hose.
Your impeller is above those water inlets where the muffs go. Need the water up to and above the impeller, thus over the cav plate when in a barrel.
 

racerone

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Dec 28, 2013
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Is the impeller 8" below water level , yes or no ?----Is the water tube properly installed ( seals in place ) at the top and bottom.----Key to drive the water pump in place.----Did you use factory parts or something else?
 
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