1 week into standup riding, bilge pump failure + out of gas in the channel of LOTO

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yamaslut

Guest
the faster a fluid (anything that flows) is going the lower the pressure it is at. so the water flowing by the cooling line should be at a lower pressure than the cooling line, because its moving faster than the air in the line. but then again i can see how it could happen because we are comparing liquids to gasses.

exactly... and should suck the water out of the lines....

he's confusing the fact that the impeller is creating pressure when spining, while the flow of water through a pump w/ out pressure from the impeller
would be at a much lower pressure, like you said, much lower than the coooing lines and sucking the water out of the lines...

I may be wrong, but I spent 3 years in the navy working w/ pumps, steam turbines and I know a little bit about how water flows
 
i was towed in a couple of weeks ago due to an ignition failure......high speed tow in VERY rough conditions..

I found water in the cyls, but figured it was from water entering and sloshing in the hull and finding its way down the carb throat...


this is one of those 1mile+ tows where you can barely hang on...
 

Matt_E

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I think you guys got it wrong. Let's have a look.

Jet pump layout:

pump.JPG


Good diagram for pump flow and pressures involved:

800px-Venturifixed2.JPG



The lowest pressure present in the driveline is in the reduction nozzle, because that's where the water has to flow faster, and thus at less pressure. (Per the Venturi effect).
This means that as long as there is any flow at all in the pump, the pressure in the stator section will always be higher than in the reduction nozzle.
The impeller creates flow, not pressure. The pressure is due to the restriction down the line.
There is no difference between flow due to towing or flow due to impeller rotation. The restriction creates the pressure in the stator section, and forces flow through the cooling line.
This is why the cooling line takes of at the Stator section, and the vacuum bilge in the reduction nozzle (that's where the low pressure is at).
The cooling flow gets stronger the faster the flow through the pump.

So, I think you're wrong.

BTW, if you have a restrictor on the flow to the stinger, the problem will be far less pronounced.
 
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Y

yamaslut

Guest
I think you guys got it wrong. Let's have a look.

Jet pump layout:

pump.JPG


Good diagram for pump flow and pressures involved:

800px-Venturifixed2.JPG



The lowest pressure present in the driveline is in the reduction nozzle, because that's where the water has to flow faster, and thus at less pressure. (Per the Venturi effect).
This means that as long as there is any flow at all in the pump, the pressure in the stator section will always be higher than in the reduction nozzle.
The impeller creates flow, not pressure. The pressure is due to the restriction down the line.
There is no difference between flow due to towing or flow due to impeller rotation. The restriction creates the pressure in the stator section, and forces flow through the cooling line.
This is why the cooling line takes of at the Stator section, and the vacuum bilge in the reduction nozzle (that's where the low pressure is at).
The cooling flow gets stronger the faster the flow through the pump.

So, I think you're wrong.

BTW, if you have a restrictor on the flow to the stinger, the problem will be far less pronounced.

I disagree :smile:
 

Matt_E

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BTW, here is what Yamaha has to say about in the Superjet Owner's manual:

yamahamanual.JPG



Do you still insist on disagreeing, or is Yamaha full of crap just like me? :rolleyes:

:thumbsdown: :moon: :fingersx:
 

Matt_E

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Sorry for picture hugeness, btw.

One more thing though....

lobsterman_BenGarvin-toned.jpg






:biggthumpup:
 
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Matt_E

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don't break your arm patting yourself on the back :rolleyes:

EDIT: Obviously I can't be trusted to detect internet sarcasm. Consider the following with that in mind.

Sorry to point it out to you, but let's consider a couple of things here:

1.) I posted factual information on a technical issue
2.) You barge in, saying it's the biggest pile of crap you've heard in a while, complete with a boatload of :rolleyes: .
3.) You then post in the respect threads about respectful posting
4.) I prove you wrong
5.) "Don't break your arm etc etc etc..."


Sorry, but you lost me. You would do well to follow your own advice on respect.

That's all.
 
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douglee25

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In the West, weighing in at a glorious 185lbs, with a record of 4-1, a lean, mean, Brapster machine, please welcome MATTTTTTTTTEEEEEEE!!! In the East, weighing in at a sleek 195 lbs, with a record of 3-2, a man who's favorite color is yellow, please welcome Slluuuuuuuuttty!!

Nothing below the belts guys... Ding! Ding!
 
Y

yamaslut

Guest
:biggthumpup: sorry... I thought I was joking

you have never heard that saying before????
It was a way of saying you were right and still not actually say it...

you are right Matt. there... Are ya happy now?
:cool2:
 
Y

yamaslut

Guest
oh come on now dont be pissy, he quoted what most would consider to be a reputable source....


yet anthoer episode of agree to disagree.....?




this is one of those arguments where it would be almost impossible to provide rock solid PROOF....

at least Doug got my joke...
 

Matt_E

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:biggthumpup: sorry... I thought I was joking

you have never heard that saying before????
It was a way of saying you were right and still not actually say it...

you are right Matt. there... Are ya happy now?
:cool2:

Damn you, Internet, with your hard-to-catch-sarcasm. :aargh4:

I apologize.
 

Matt_E

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BTW, the fella on the "Owned" picture has been trying to run for President for a few years now.
 
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