water coming from upper unit after impeller replacement

[kny]

Honda BF75 outboard. Replaced a cracked impeller. After replacement, large amounts of water coming out of upper unit and much weaker pee stream than when all was working properly.

Video here shows much better than I can describe.
https://photos.app.goo.gl/jdKcJiGbG4ugzd427

Thoughts on what the issue could be?`

 

[pvanv]

Looks like water pipe is not connected.

 

[ahicks]

Oh boy, for sure that's not right. You need t pull that down and confirm both ends of the water pipe, the one that leads from the top of the pump to the bottom of the engine, are seated properly in the right location.

 

[Sea Rider]

You need t pull that down and confirm both ends are seated properly in the right location.

Won't see a perfect water pipe/grommet alignment match on any lower leg while being pulled downward due to both parts being well hidden inside lower middle leg for a clear visual inspection. It's a feel thing when aligning water pump's upper grommet to lower pipe when putting back in or testing running engine ON on muffs, barrel..

Happy Boating

 

[ahicks]

On further thought, the top of that pipe is held securely in place. It cannot be removed from the bottom of the engine without a lot of disassembly. Point being, the top of the water pipe being uninstalled is not likely an issue.

That leaves 2 options. The first is some type of mechanical failure - which is not likely unless the engine has an extensive history of salt water use.

The second, is that the lower unit was not installed properly, with the water pipe lined up on the water pump. That pipe, though it is secured at the top, is free to turn. It's very possible to turn it to the point it no longer lines up on the pump......

In the second case, I'm amazed the engine is getting enough water to pee. Fingers crossed for the OP!

 

[kny]

OP here. Thanks for all the replies. Boat is at a 2nd home, but will report back in when further diagnosed. Never seen salt water, so most likely ahicks and option 2 are the answer. Thanks again all!

 

[kny]

Now that the boat is out of the water I took off the lower unit and attached a hose directly to the water tube. Result is water comes out telltale but also a good bit of water flows back down and out the lower unit.

I do not believe it possible to attach the lower unit and have the impeller not properly aligned with the water tube given the nature of the impeller housing.

So, this suggests to me a problem in the water tube further up.

Thoughts? Would one expect a hose directly attached to water tube to have so much flow back down and out the lower unit? Or is that indicative of an issue in the water tube?

See video. Apologies for the first 15 seconds or so; tough to use phone and hold hose on tight and turn water on.

https://photos.app.goo.gl/jurXF57BVWvfvcZd7

 

[ahicks]

I see nothing unusual there. The water goes up that tube to the bottom of the motor, where it splits off to the water pisser, then the majority of the water flows over to the exhaust cover on the LH side of the engine, circulates through that, to the cylinders and t'stat, though the head, and at the bottom of the head, out though a port that leads to the exhaust. From that port that dumps into the exhaust (to help cool and quiet the exhaust gasses) it is dropped into the the muffler and lower unit where it exits the engine with the exhaust.

Has this engine been hot? Are you getting any water in your oil?

 

[kny]

Engine has been hot once. Impeller cracked and engine overheated to point of alarm going off, then shut down. Impeller replaced, but once new impeller installed it barely pisses and dumps water out near top of lower unit as shown here:
https://photos.app.goo.gl/jdKcJiGbG4ugzd427

Presumption was impeller housing was not aligned with water tube, but I do not believe that be correct as lower unit cannot be reinstalled flush and tight without impeller housing aligned properly. So, I thought maybe issue was at the upper end of the water pipe. But, attaching hose directly seems to show all is fine.

So I'm stumped.

 

[ahicks]

If you are absolutely sure that pipe is going into the water pump, and the grommet there is in good shape, I'm thinking you need to see a pro. Not the summer help that works at a marina, but somebody that really knows what they are doing with a Honda.

I'm wondering if there is a possibility that pipe is cracked? That might be something to check out carefully with a good flashlight.

I've done a bunch of work on them, but I've only seen one with a similar problem and it was a 50. That engine was a salt water engine, and it also "featured" a small amount of water getting into the oil. Despite having that engine completely apart twice, I never did figure it out. Ended up replacing the short block.

Here, with a fresh water engine, I doubt you have anything that serious going on. It's much more likely something simple. Wish I could be more help! -Al

 

[kny]

I appreciate your help. As much as having the motor fixed, I just want to know what the problem is! Curiousity kills!

 

[ahicks]

Yes, exactly! I know the feeling! That's why that 50 was pulled down a second time! At that point, when it still did the same thing, it was time to move on. The gaskets alone to R&R the block and head are well over 100 bucks. Point being, as curious as I was, it was time to get on with it.....

 

[Sea Rider]

Where old pump impeller vanes complete when impeller was removed. If broken some rubber pieces could have made its way up powerhead and are clogging some water passages ? Remove thermo housing and thermo, check that the internal thermo area is clean, nothing is obstructing the water passages...

Happy Boating