A couple trips back i noticed my motor peeing weaker than it usually does. its usually a pretty decently strong stream even when on muffs and idling. Noticed before last trip it just wasnt the same so decided to change the impeller (been about 2 years but hardly fished at all last year) hoping thatd be the fix. It didnt fix it and the stream still pees weak.

I did use the boat last week and ran it full throttle and quite a bit running all over the lake. When im full throttle there is a decent stream coming out but nowhere near how it was before. I also touched the pee stream while the throttle was about 1/3 down and even though the stream was real weak the water was not hot at all or even warm (water temps are still in the low 60s at my lake tho).

Do I need to get this fixed and over to a mechanic before I use it again, or should i be ok running it a while? any ideas what can be the issue here?

If you can, take that hose off at the motor and blow it out. Mud Dobbers love those pee holes. Had mine clogged two times. Now I roll a piece of paper and plug it off.

Get a few inches of weed eater string and stick up in the there and work it around. It just takes a little pebble or gravel that got sucked up the intake to partially clog it.

I've done that and also detached it from under the cowling and blown it out with air there. Always works.

unfortunately Ive dont both of those things and no luck....thats why im kinda worrying. Im wondering if I gotta go deeper than just the hose to get whatever is obstructing it to clear. Hopefully not cuz that means mechanic but if I gotta do it i gotta do it

I would unplug the hose off the barbed fitting where it comes out of the block and check the hose for no obstructions. Maybe even get a small piece of tube and just try it that way you know for sure. If that’s not it pull the thermostats and check for trash in them. Also does the stream increase when you speed up the motor? Or stay the same.

Sometimes you gotta change the impeller housing. I've had to do it a time or two over the years. Got a water pressure gauge?

stream does increase when i speed up.

Im pretty sure ive done everything aside from tearing the motor apart....except the thermostat. I actually ordered one on Thursday and itll be here wednesday. I think that can do it from a bunch of googling I did last week....and really hope it does! LOL

Let me ask....Im hitting the lake before wednesday. I was just planning to keep an eye on the stream....do you think I should open up the thermostat to try and clean it out before making the trip...or just use it for the day as is?



no water pressure guage. what do you mean impeller housing? I buy the impeller kit and replace all that stuff. the only thing thats not included is the metal shell it all sits in....and that thing was still in good shape though. Is the housing that metal shell?

The housing is the plastic top that slides down that you bolt down. Sometimes it gets warped or if someone has started the motor out of the water, it will melt.

Correct, I've had issues a couple times where I had poor water pressure after replacing an impeller and could find nothing wrong with the housing. I'd get a complete water pump repair kit which includes the housing and viola' the issue disappears.

What does a complete water pump kit look like? This is what I have ordered and used when Ive changed my impeller. Is what you all are describing in this...or is it something else?

Thermostat gets here tomorrow. took out the old one...and there was some sand and it looked old (and likely never changed since the bolts were untouched)...but put it back in and still seeing the same weak stream. I hope the new thermostat will fix it....if not I know this is going to not only get expensive, but a big pain in the [censored]. I dont have a mechanic i trust within 2 hours of me....so might be taking a trip to drop off a boat somewhere 🤦‍♂️

also, the thing all that stuff goes into and goes over the whole thing is metal....is that the housing you all are talking about?

The housing appears to be a phenolic resin type material with a stainless steel liner. The above pictured kit is an impeller replacement kit, not a water pump rebuild kit. I normally buy the impellers alone and have gotten them for as little as $8 each on Ebay. Every 3rd time or so, I will have to replace the housing, so I order the complete kit.

You mean the thing I circled in red, right? Sorry Im slow! LOL

That thing is metal in my motor. Its in pretty good shape. I usually just wipe it down with rubbing alcohol to clean off the surface and it looks good after.

Im actually in the mercury parts finder now and the thing called "HOUSING ASSEMBLY Water Pump Upper" is for sure metal comparing the diagram to my motor. This video is pretty much what I see when I take my LU off.

https://www.youtube.com/watch?v=ij3U12UwQdM&ab_channel=D-RaySmith

It probably wont link to it direct...but im having trouble finding a water pump kit in the mercury parts finder. I just see the things that I bought and replaced (similar to the picture I posted before). Ill probably call mercury (not looking forward to it LOL) to see if they can direct me to a water pump kit for my motor...because that might be my next step before a mechanic. https://public-mercurymarine.sysonl..._KEY_VALUE&langIF=eng&langDB=eng
(EDIT: It dont go to the parts finder for my motor 🤦‍♂️)

Even though blowing out the thermostat didnt fix it....im really hoping the new one will do the trick since the old one looked old as [censored]! LOL im pretty sure it has never been changed because the bolts have a black flexseal type spray all over them, and they were completely undisturbed....compared to it peeling where I was using the wrench on em.

Thank you for the tips! its always good to get some feedback on something you are totally in the dark on! LOL I hope I can figure this one out....I bought a 2 stroke specifically so I could work on it myself. I was told 2 strokes were a lot more of a simple machine than a 4 stroke...so Im hoping I can get away with doing the basics. Im hoping the whole water pump is gonna be within my range of abilities!

Yes, the piece circled in red and the stainless steel cup(liner) below it that fits into the housing are what I am referencing. I looked at the video link you posted and see that it's a different design than my V-6 Merc but still the same idea. The metal housing in the video serves the same function and the plastic one in the above pic. it holds the stainless steel cup/liner that the impeller rides in. Good luck with the Mercury parts finder, it frustrates me quite often. I have a great dealer about a mile from my house, he helps me find parts and gives advice when i get in over my head. Been running outboards 50+ years and have only needed to put one in the shop twice, once was because I was too lazy to spend the time diagnosing an issue that had several possible culprits and the other was a powerhead rebuild that was above my pay grade. A good resource for parts and advice is iboats.com, good forums and links to parts suppliers both factory and aftermarket. Good luck