# Help! 2000 Yamaha 9.9 won't pee while running



## mxracer19 (Apr 23, 2009)

Hey guys...I'm new to outboards. I recently picked up a used 2000 Yamaha 9.9 HT. When I connect the hose to the flush connection I get a nice stream of water out the pee port. When I put the engine in the water for the first time and started her up, nothing came out the port. I checked the intakes on the lower unit and theyre clear and when I run the motor on the hard hooked to the flush I get a solid flow out the lower end exhaust.

I talked with someone at a local retail store and he suggested that the thermostat might be between the pee port and the water pump, so if the thermostat was closed then I wouldn't see a discharge until the block heated up enough to open the thermostat. I read elseware that I should see a steady stream of water at all times. Im at a loss...does anyone have any ideas before I break open the lower end to check out the impeller?

I have a T9.9 EXRY...2000 two-cylinder 9.9 fourstroke, high thrust with remote and electric start.

Thanks,
Matt


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## Squidd (Sep 26, 2011)

No thermostat, bad impeller...


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## bratzcpa (Oct 18, 2011)

Replace the impeller in the lower unit. This will be a rubber gear shaped thing. it's good practice to replace this every year or two anyway. If the previous owner had run the motor dry (out of the water, for example) for even a minute or two, this will likely totally ruin the impeller. 

The good news - pretty inexpensive repair. But do it NOW before running it again.


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## gershel (Feb 4, 2001)

Try a few simple things first. Try inserting a small wire or toothpick into the pee hole to clear any obstuction. Sometimes a small bug or spider is all it takes to stop the flow. If that doesn't work, remove the thermostat,(easy) and see if you get a flow. If neither works, you'll probably have to remove the lower end, not always easy to separete.
I suspect one of the first 2 remedies should work. I have 2 Yamaha 9.9 high thrust engines. 
Marc


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## tipitina (Jan 17, 2012)

I vote impeller... Doesn't hurt to change it anyway. Should be fairly inexpensive for that motor, and easy once you do it. Watch a youtube video or two. Really nothing to it if you're mechanically inclined at all. Wouldn't hurt to check thermostat too.


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## -OvO- (Dec 31, 2011)

Replace the impeller and the thermostat both, unless you have maintenance records that show it was done recently. The motor is 12 years old, it's more than due.


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## mxracer19 (Apr 23, 2009)

That's the direction I was thinking of taking. I picked up an impeller and I'll most likely get to it today. I read a few articles talking about the layout of the coolant passages and from how it sounds I might have a few blocked passageways within the block as well. I'll pull the lower end and thermostat and give a few shots of compressed air through the different nipples and tubes before reassembling the lower end with a new impeller.

I'm down here in Florida where the water temps don't dip below 60. If the thermostat is bad do I really need to replace it on this motor?

Thanks for the help,
Matt


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## pvanv1 (Nov 16, 2007)

Do the wp kit, not just the impeller. Same labor, slight cost increase. Yes, you need a stat or the plugs will foul.


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## gershel (Feb 4, 2001)

Since you're set on removing the lower end, instead of a possible simple fix, you may find this helpful.
PDQ Forum • View topic - T9.9 lower end removal questions

Google "mud daubers in outboards pee hole"


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## mxracer19 (Apr 23, 2009)

Just an update for clarification...

After hauling the boat when the engine wouldnt pee I hooked it up to the hose at which time the flush water exited the pee hole. That told me before I broke it apart that the discharge wasnt clogged. I opened the top cowling and removed the thermostat cover only to find that my engine doesn't have a thermostat. The previous owner removed it. I poured water down the thermostat and it exited through the discharge and lower telling me that I most likel;y dont have a clog in those lines. I dropped the lower end but when I inspected the impeller it appeared intact. I replaced the impeller and ordered a new thermostat and thats where Im at now.


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## gershel (Feb 4, 2001)

Since all your lines appear to be clear, and the impeller "appears" to be intact, it should be checked for slippage. Sometimes the rubber part breaks away from the center collar, or somehow the shaft key gets dis-lodged. Try holding the impeller while turning the shaft, to see if anything slips. If that's OK try checking the shaft itself for any slippage.
Concerning the thermostat, The PO probably removed it as a temporary fix for overheating, but a faulty thermostat would not cause a pee hole flow stoppage.
Marc

P.S. Since the lower end is already off, the impeller should be changed regardless.


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## chdawebb (May 22, 2016)

Well its May 2016 and I broke out my sailboat for the season. It has a Yamaha 9.9 outboard. I'm not sure exactly of the model year but between 1997-1999. As I do with with my boats every year i check the engine after winter storage. This year i have no cooling water coming out of the pee hole. I checked for clog in the exiting tubing and found it clear. I hauled the boat off to the marina for repair. After getting home I did some research and discovered there is a thermostat. Now I wonder if i prematurely took the boat to the marina without doing my diligent troubleshooting. Did I do the right thing or can it be something as simple as a thermostat? Would this be something the marina would check or will they just jump in and remove the lower unit? 
Thanks,
Chuck
[email protected]


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## capecodda (Oct 6, 2009)

Chuck

Most often when this happens, I've found a blocked pee hole (as has been mentioned above). That's the easy fix.

Dropping the lower unit is sometimes a pain, but after you do it once it's not too hard. There is typically a way to disconnect the shift linkage, then if everything isn't too rusted up, loosen the bolts and off it comes. Then doing the impeller, might as well do the whole pump rebuild kit which includes some gaskets, wear items, and other stuff. That part is pretty straight forward. When you put it back on, there's some fussing to make sure the tube which delivers water up to the engine is aligned with a gasket on the pump, and the shift mechanism is reconnected and adjusted correctly. I've done this on 3 different small outboards, and they each have a different way of doing the shift linkage.

If there is a thermostat, that's a good theory on what's wrong. Think about this poor thermostat living in salt water for a few years and gradually corroding away. Much easier to replace than the impeller. 

Marina's might do anything based on the skill and experience level of the tech. Might want to suggest they replace the thermostat first, worst case you've got a new thermostat before they do the harder job. Unless everything is frozen together, if I can do a water pump in an hour, I imagine someone who actually knows what they are doing would be faster so this shouldn't cost a fortune.
Parts are relatively cheap by boat bucks standards.

Good luck!


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## Tanski (May 28, 2015)

I'm not sure the thermostat would cause your problem.
Just looked in my manual and as far as I can tell you should still be getting flow even if the thermostat is closed, water should just bypass and flow out the exit. Nowhere does it mention no cooling flow with a stuck thermostat.
They claim the only way to know is to remove it and do the hot water trick. Nothing about flow as a diagnosis.
Based on the manual and your description it sounds like the impeller or blocked passages.
I know mine flows when the thermostat is closed, lake is still just above freezing and haven't been out yet in temps above 20C. I have good flow right from start up when in theory the thermostat should be closed.
LOL unless it's been stuck open for years....


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## chdawebb (May 22, 2016)

This engine in on a 26 foot sailboat (on trailer). I didn't want the neighborhood association to start and complain. I already had it parked in front of the house for two days. So off to the marina. If it were on a smaller boat i would has exhausted my troubleshooting ability before taking it to the marina.


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## capecodda (Oct 6, 2009)

Hey I think Tanski thinking is right, take back my comments about thermostat, but if it's been in there for a while might change it anyway because it will corrode and go bad especially if you are in salt water. Good luck on this, let us know what it turns out to be.


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