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BF90 Water Pump Testing - Water pouring out of the side covers - Is this normal?

D

Dcav

Member
I changed out the water pump on my BF90. When doing a test, water is pouring out of the bottom of the side covers/cowlings. Is this normal? It's not overheating and the pee stream is super strong. Here is a video that shows what its doing: https://youtu.be/J1YTqkl_mxU
 
Thanks for the reply iang6766. I did pull it again to double check everything because I had the same thought. Everything seems to be lined up and connected right - of course I can't see in there once everything is in place, so can't be 100% positive. What makes me think the tube is inserted correctly is it has a very strong pee stream and water is circulating to the top of the motor, and it doesn't overheat. Was thinking it might be the Water Pressure Relief valve, but I pulled that as well and it looks good. I guess I will pull the lower unit again (3rd time) and check it again - just seems odd.
 
Just don't leave it, this is a common issue and will result in water getting into the flywheel cavity causing corrosion to lower crank seal track and starter motor. Best to replace complete water pump since there could also be excessive leakage between the impeller and pump liner
 
iang6766 said:
Just don't leave it, this is a common issue and will result in water getting into the flywheel cavity causing corrosion to lower crank seal track and starter motor. Best to replace complete water pump since there could also be excessive leakage between the impeller and pump liner
Click to expand...

I plan on digging into it tomorrow, but definitely will order the full WP kit just in case. I haven’t put it in the water yet, just ran it on the house hose and in a bucket so far. I will make sure it’s good to go before I take it to the lake for further testing. Also will check/change the gear oil just in case. It is a little concerning. Also curious if a bad or misbehaving Water Pressure Relief valve could cause this issue because I was checking that as well the same weekend I changed out the water pump?
 
What parts are replaced when doing a basic kit?

If they did not include the pump housing or insert/liner, I would have a real close look at those to see if the plastic housing didn't get hot enough to let the stainless insert move a little. Often you'll actually see a grove worn into the driveshaft by the liner when that happens. -Al
 
Alan Hicks said:
What parts are replaced when doing a basic kit?

If they did not include the pump housing or insert/liner, I would have a real close look at those to see if the plastic housing didn't get hot enough to let the stainless insert move a little. Often you'll actually see a grove worn into the driveshaft by the liner when that happens. -Al
Click to expand...

Here are both kits - the basic kit is #1: https://www.boats.net/catalog/honda...bf90dk0-lrta-2007-and-later/impeller-pump-kit

When I took her apart, all components looked very healthy and no obvious signs of excessive wear. The last kit was put in about a year ago with no issues. The motor only has about 360 total hours on her.
 
An idea maybe, to verify your water tube IS in fact sliding into the grommet on top of the pump, and further, exactly how far it's being inserted.

If you have an O-ring assortment and can find one that will fit that tube, grease up the end of the tube so the O-ring can slide easily on it, set it about 1/4" from the end, reinstall the lower, then pull it to reveal how far the o-ring is sliding into the grommet. Should only take a minute, and can verify there's nothing going on there beyond doubt!

If you can't find an 0-ring, maybe a rubber band would work...
 
Just believe me, this is a common problem with these pumps. If you leave it you will do a lot of expensive damage, especially if you use it in saltwater. Another thing I do with the new pump kit is glue the liner into the plastic housing.
 
Alan Hicks said:
An idea maybe, to verify your water tube IS in fact sliding into the grommet on top of the pump, and further, exactly how far it's being inserted.

If you have an O-ring assortment and can find one that will fit that tube, grease up the end of the tube so the O-ring can slide easily on it, set it about 1/4" from the end, reinstall the lower, then pull it to reveal how far the o-ring is sliding into the grommet. Should only take a minute, and can verify there's nothing going on there beyond doubt!

If you can't find an 0-ring, maybe a rubber band would work...
Click to expand...

I did what you asked. See the results in the latest video - you can skip to 7:47 of the video for part 3: https://youtu.be/vaNBmo5NE8A
 
iang6766 said:
Just believe me, this is a common problem with these pumps. If you leave it you will do a lot of expensive damage, especially if you use it in saltwater. Another thing I do with the new pump kit is glue the liner into the plastic housing.
Click to expand...

Agreed - I do run it in salt water a lot so thats my biggest concern. Check out the latest video and let me know what you think: https://youtu.be/vaNBmo5NE8A
 
I think your test with the drill turning the pump was a good idea, and likely identified your issue. I think maybe some water coming from the area where the drive shaft enters the pump may be OK (like you said, there's no seal there), but not like what you have going on. The top of that stainless cup SHOULD seal against the top side of the impeller to minimize the water escaping there. Clearly, the impeller is NOT sealing against the top of that cup as well as need be. I believe that's your issue.

If it were mine, that's where my focus would be.....

new plastic housing
new stainless cup - because I doubt you'll get that one out without deforming it
and a new OEM (not aftermarket) impeller

coat the new impeller with grease (including top and bottom)
coat the cup with grease
coat the steel bottom plate with grease
assemble
then try your drill test again
 
Alan Hicks said:
I think your test with the drill turning the pump was a good idea, and likely identified your issue. I think maybe some water coming from the area where the drive shaft enters the pump may be OK (like you said, there's no seal there), but not like what you have going on. The top of that stainless cup SHOULD seal against the top side of the impeller to minimize the water escaping there. Clearly, the impeller is NOT sealing against the top of that cup as well as need be. I believe that's your issue.

If it were mine, that's where my focus would be.....

new plastic housing
new stainless cup - because I doubt you'll get that one out without deforming it
and a new OEM (not aftermarket) impeller

coat the new impeller with grease (including top and bottom)
coat the cup with grease
coat the steel bottom plate with grease
assemble
then try your drill test again
Click to expand...

Yeah - appreciate the input. I plan on ordering the "complete" water pump replacement kit from Boats.net today:
PUMP KIT, IMPELLER | (Optional).
06193-ZZ0-000 [COLOR=#009A00 !important][FONT=&quot][/FONT][/COLOR]
 
Just my 2 cents.

I agree with changing out the pump. It's as Alan has already indicated....Maybe there is just enough wear to the housing that it's allowing too much clearance there.

At worst you will end up with a spare pump if that's not the culprit. And, if it isn't....

And you still suspect restriction of some kind, compare the condition with everything hooked up with what it might be with the water tell-tale fitting removed from block. That fitting provides a bit of restricted flow so the issue should improve as you reduce restriction.

You've put in a lot of work here and it's been very instructive to me so, thank you.

Hopefully the new pump will solve the mystery.

Good luck.
 
That is exactly why I suggest a complete water pump replacement, as said, it was a very comon problem for a while and I have seen two crank seal tracks so corroded they had to be removed and repaired. The new pumps have a better impeller crush but I still epoxy the liner to the housing too be sure it can't move. Basically this pump is bad design and interestingly the new motors now have a completely different low volume pump, I assume because the old one simply pumped too much water and I say this because that same pump was never an issue on the 115, 130, 135 and 150.
 
iang6766 said:
That is exactly why I suggest a complete water pump replacement, as said, it was a very comon problem for a while and I have seen two crank seal tracks so corroded they had to be removed and repaired. The new pumps have a better impeller crush but I still epoxy the liner to the housing too be sure it can't move. Basically this pump is bad design and interestingly the new motors now have a completely different low volume pump, I assume because the old one simply pumped too much water and I say this because that same pump was never an issue on the 115, 130, 135 and 150.
Click to expand...

Roger that - was just trying to eliminate any other things since everything worked fine before I did the change. However a new complete pump kit is on the way.
 
iang6766 said:
That is exactly why I suggest a complete water pump replacement, as said, it was a very comon problem for a while and I have seen two crank seal tracks so corroded they had to be removed and repaired. The new pumps have a better impeller crush but I still epoxy the liner to the housing too be sure it can't move. Basically this pump is bad design and interestingly the new motors now have a completely different low volume pump, I assume because the old one simply pumped too much water and I say this because that same pump was never an issue on the 115, 130, 135 and 150.
Click to expand...

Thanks - I have ordered the new complete pump kit. Should be here in a couple days and go from there.
 
I also suggest you take the starter motor off and check that the flyweel housing is dry and not starting to corrode.
 
If you are going to go with the epoxy plan, just realize that epoxy is going to need to be spread REALLY thin! The parts are not designed for use with epoxy, so there is no additional clearance available for it.......

Make sure that cup is fully seated, so the sides are not protruding below the housing.
 
I'm fine with the epoxy solution. Dcav has likely considered the issue already. My note intended just as a caution in case he hadn't considered it.
 
Alan Hicks said:
I'm fine with the epoxy solution. Dcav has likely considered the issue already. My note intended just as a caution in case he hadn't considered it.
Click to expand...

Appreciate the tip and consideration. I will ensure a thin coat is applied and everything seats/seals properly. Just waiting for the new kit to arrive and we shall see if I just wasted $179 :).
 
Happy to hear you solved the issue!
Thanks for following up and posting your end results! This is helpful to others who may have same issue and want to see the solution.
 
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