OX66 not pumping water after impeller replacement

[Tapdatbass]

2000 OX66 225 with HPDI lower unit. Last time on the water everything was fine. Started engine in the driveway before going out on the water last week and I was not getting water out of the weep hole. Replaced impeller and still no water pumping out of weep hole. Below is all I’ve done so far:

• Replace impeller as well as entire kit (gaskets,orings, etc)
• old impeller was all intact so I don’t believe any pieces would clog anything.
• Verified impeller is spinning correct direction
• woodruff key is in
• greased everything as it was installed
• ran engine on single side muffs and with lower unit submergered
• hooked up hose to flush hookup and had water coming from everywhere it should. Weep hole, lower unit water pickup, etc.
• removed poppet valve and cleaned out. It did have sand and dirt...
• drive shaft is turning with engine running and will go into gear.
• I removed lower unit a second time and removed impeller cover then blew compressed air and water into the opening under the impeller in hope to clear anything that may have been clogged.
• I followed the water outlet tube as far up as I could see when installing lower unit. I lost sight before I can say with absolute certainty that it meet up with the tube but I’m confident the tube met up.

After all of this I still have no water pumping. I’m lost. Got a tournament in 5 days and I’m stressed. I appreciate all of your input.

[javelin90]

After you made all the repairs did you test it on muffs in driveway or on the lake? Is the rubber grommet intact where the waterline comes up from the lower unit to the inside of the motor housing? Have you checked the two thermostats sit on top, one per side? Use a piece of coated wire small enough and run it inside the hole where water should be coming of the weep hole.

[Tapdatbass]

After you made all the repairs did you test it on muffs in driveway or on the lake? Is the rubber grommet intact where the waterline comes up from the lower unit to the inside of the motor housing? Have you checked the two thermostats sit on top, one per side? Use a piece of coated wire small enough and run it inside the hole where water should be coming of the weep hole.

Tested on the muffs as well as in a tub of water. The rubber grommet is intact. Water comes out the weep hole when water is hooked to the flush connector. Wouldn’t the engine pump water whether the thermostat was open or closed?

[Amistad Tackle]

Muffs on an OX66 can be tricky. A single sided muff may not supply enough water to get it to pee. Your water pressure from the hose may no be high enough. I turn my hose on as high as it will go. With my double side muff I have to hold it on with my hands and allow the water jacket to fill and for it to start peeing with just the water supplied from the hose. Then I can fire the motor and get it to pee. With a single muff maybe not enough water is getting in. Take it to the lake and see if it pees. It sounds like the repair you made was done correctly.

[Bass Junkie]

Have you actually tested it in the lake?

[Tapdatbass]

Muffs on an OX66 can be tricky. A single sided muff may not supply enough water to get it to pee. Your water pressure from the hose may no be high enough. I turn my hose on as high as it will go. With my double side muff I have to hold it on with my hands and allow the water jacket to fill and for it to start peeing with just the water supplied from the hose. Then I can fire the motor and get it to pee. With a single muff maybe not enough water is getting in. Take it to the lake and see if it pees. It sounds like the repair you made was done correctly.

I ran it with the lower unit submerged in a tub of water as well as on the muffs. It has always pumped on the muffs for me

[bpicinc]

Only thing that I would do different is only put grease to hold woodruff key in shaft and on o-rings.

[Amistad Tackle]

I ran it with the lower unit submerged in a tub of water as well as on the muffs. It has always pumped on the muffs for me

Well then something with your repair isn't right, or you have a blockage somewhere.

[ifishinxs]

Isn’t there a water line from the pump to the upper housing. It’s been awhile but I seem to remember it’s right in front of the shift shaft. Would be easy to forget about and might cause your problem.

[javelin90]

+1 on upper hose at shaft. First time I did mine the rubber gasket sits between the upper water housing by the shat and the lower hose on lower unit were not seated correctly and my water pressure was low. If you were closer I'd offer to help you. I love to see them Ox66 still running on water.

[Tapdatbass]

Thanks for the help all. I was able to get a loaner boat for my tourney and I’ll be tearing the boat back apart this week to take a better look at the water line from the upper housing.

[Tapdatbass]

Have you actually tested it in the lake?

Well, come to find out my tub of water was not high enough. After triple checking everything I finally took it to the lake and it starting pumping water. Apparently the water level needed to be higher than the impeller. My question now is why did it all the sudden stop pumping water on muffs or in a tub of water when this engine has always pumped water in the driveway no problem?

[WisconsinF]

I'd replace that impeller again. No telling what all that running with "possibly" no water passing through did to it. Possible heat damage?

[Tapdatbass]

Its been 2+ years with this same impeller and never any overheating issues. Still it's an inconvenience not being able to run the engine at home on muffs. I'd like to revisit this. Any ideas why it pumps strong on the lake but will not push water through the weep hole when hooked up to muffs (double intake muffs)????

[headhigh]

What is your water PSI when running on the lake?

[1ranger487vs]

Have same motor does the same thing. Pump moves more water than you can supply at home. Can run mine at home enough to check things out before it gets alarm. On lake. 5 psi idling or less. Running 15 to 20 Water supply is the answer

[Coach185]

Not sure if my lower unit is the same as yours but it does exactly the same thing. Running off of muffs not enough water to weep out of the pee holes. I won't run my V150TLRB off muffs any more, I just use a flush tub.
My Suziki DF140 on my pontoon boat runs fine on the muffs, just not the Yamaha.

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[davesz518]

I believe the water tube is not mated correctly. Easy to miss on re assembly.