2 stroke mercury 25hp installing a new outboard water pump, impeller and coldstart

replacing an outboard water pump and impeller on a 1998 mercury 25hp 2 stroke outboard engine.
USA
pump kit (OEM) seen in this video
amzn.to/2teSs3p
or
amzn.to/2sJH5is
Canada
amzn.to/2sZ1sqJ

[@sparlin88]

I want to thank you for helping me solve a problem. I just bought my first outboard . A 1999 25hp mercury . Bought from a guy about 100 miles away . Went there and it fired right up and ran smooth . Paid him $1,200 and took it home . Put it on this boat I just bought also and started it up with no problems . Went to put it in gear and didn't go in forward or reverse. I called the guy complaining and was told its my problem basically. So got here on youtube and found your post on changing water pump so went out and found out his great mechanic he bragged about didn't put the locking pin back on the gear selector shaft . Its fixed now and my wife is son happy . We both believed we were ripped off by a guy with no conscience or heart . Just greed. Thanks so VERY MUCH !!!!! YOU ROCK !!!

[@partsbenttoys]

6 yr old vid, still useful and helping ppl get by. thank you, great video btw

[@aaronm1375]

Thank you, excellent video. My nephews dry started my Mercury 25 when I wasn't around, and it was recommended I replace the impeller before taking it out on the water again. I was dreading it, but after watching this video I am confident I can handle it. And I was gracious to my nephews since they didn't know how bad dry starting is, but they do have strict instructions on what will happen if they ever dry start it again. Thank goodness one of them tattled to me, or I might have never known.

[@upnort1842]

Thanks for the video! I like how you very clearly point out all the bolts and the retainer!

[@laloromero6860]

I paid someone like $200 because I thought it was going to be way to hard for to work on the lower unit. Your video makes it possible thanks!

[@channel-gj8pl]

Thanks for the information on You Tube. I changed a water pump for a friend today and it went just as you showed. This improved my chance of having a successful repair. The engine was a 1991 Merc 25.

[@t.d.mich.7064]

Thanks for the heads up about the shift linkage disconnect! I've done this job before on smaller Mercs without electric start, I would not have known to look for this before trying to drop the lower unit. Good info!

[@alexmillwood1433]

Thanks heaps mate I've just bought one of these after watching this I feel confident to do the job myself and learn a lot more about these great little motors cheers for saving me some cash to every little bit helps at the moment

[@521VX05]

Excellent video. Was a great help in getting our 2000 25 EH changed out this week. Only difficulty we had was the shifter wanting to change gears as we fed it up the tube when reinstalling the lower. Just took some trial and error.

[@johnvyverberg3283]

Thanks for the tip on removing the clip for the shift linkage! I was puzzled by this until I saw the video. BTW, my engine is a 9.9 Belgian 2 stroke.

[@bart2u]

I had no ideal where the release was for shifting linkage. Thankyou so much for making this vidio. The macanic wanted 1 and1/2 hour and up to $100 dollars for parts u saved me $400

[@darrylhenchie4765]

A brilliant tutorial. Thanks mate. Just purchased a dinghy with 99 Mercury 25 hp. You're video was a brilliant and timely find. I've subscribed😁

[@tomschwartz2811]

The water tube came out when I dropped the lower end. With it going so far up in the motor, it's not that easy to re-insert it. I took a 5/16" wooden dowel and put it into the lower tube end. It's a tight fit and makes it a lot easier to re-insert the tube. The straight end of the tube goes up.

[@fredrikh9299]

Thank you for generously sharing your know-how and taking the time to make a very instructive video! Regards from Sweden.

[@robertcook1065]

after watching your video a bunch of times I did replace water pump today and cured the problem. thanks

[@TheRfleming]

You were very informative and you didn't talk to much.Thank you.

[@williammadden9558]

I cant say thank you enough! I have a 1989 MERCURY 25 HP outboard. One place wanted $350 and others didn't even return calls for this job. $46 for the kit on Amazon. Your video was excellent. You cover everything extremely well. Only difference on the 1989 engine is the carb cover and starter are on the port side of the engine. I only had 1 issue getting the o ring to stay on the housing cover. I had to stretch it a bit, which took some doing, so it didnt want to roll off. Once again, excellent video and a sincere thank you!

[@ericbrown9835]

Excellent video. I'm not at all hesitant to now take on my impeller change out.

[@JBOutdoors]

Thanks for a great walk through video. I've done a smaller 7.5 hp mercury and wanted to compare as I'm doing one on a similar motor to yours.

[@thomasbrock4705]

Thanks man,you saved me a mechanics bill.

[@deanbowe4070]

Just used your video to change the impeller on my mariner motor, thanks!

[@williamdabinett6222]

Thank you so much I’m so happy you done such a clear video Just wound Fil I’m from Australia thanks mate 🙏

[@kevinapel3027]

Best video for this subject I have seen. Thanks for helping me out! You missed your calling. You should make instructional videos for other things. Thanks again

[@ShnitzlHaus]

+Kevin Apel thanks Kevin :). I do what I can, but have to work a job that pays the bills to. Life :)

[@John-of5sh]

Excellent video-Definitely on my "To-Do" list. Thanks so much for sharing your time and expertise!

[@classicbikerx3588]

Wow, so much harder than the bigger units due to shift linkage! Good vid

[@cagleoutdoors6384]

This video saved me a ton of time thankyou your a life saver

[@captlarry-3525]

thanks ! my 20's are older with a screw holding the shift rod,, but I am sure the hints still apply, I am now a whole LOT more likely to do this important maint job !

[@tandk86]

Great work! Mine is flowing water like I never seen with pressure

[@stevejones6111]

Great Video. I would suggest putting a little light grease around the vanes on the wear plate and the top of the impeller housing so you have lubrication on first start up before the water reaches the impeller.

[@ShnitzlHaus]

Agree. I believe I used petroleum jelly in the video. Anything works.

[@dylandavis4074]

@@ShnitzlHaus isn't petroleum jelly, or any petroleum based grease not good to use on rubber parts? Causes them to swell? This is what I've learned with brake parts on vehicles? I use Syl-Glide for rubber brake parts. I've seen petroleum based grease degrade caliper slid pin boots and caliper seal. Great video though, I'm about to do this with an outboard I just bought.

[@ShnitzlHaus]

Yes you are correct but realistically it’s going to get washed out fast and argumentative points would be the impeller is a wear item and needs to be replaced regardless. Also most of these impellers are likely seeing many dry starts from sitting in storage to pulling the boat out of water for lengths of time.

[@russwentz3957]

Thank you, thank you, thank you! Between diagrams and service manual, wasn't clear on the shift linkage. Very clear, well done video. Thank you for your time to pass it on.

[@freddynews6478]

Excellent video and description narrative.

[@DougLandry-ub4dg]

Thank you just did mine . Your video was a great help.

[@jackgunter3999]

Your video just saved my day!!! Thank you

[@ct1762]

that shift rod clip is a bit easier than my 82' 18 merc.. ingenious design. you do want to slap some 2 stroke oil inside the pump housing and on the baseplate, however.

[@BladeRunner.43]

I thought I had the wrong impeller I'm like well that doesn't fit lol thanks for the vid

[@morgan4xl]

If you try to start the engine out of water with a new water pump you will destroy the rubber impellor in less than five seconds. A very old and worn pump will last somewhat longer but it is a horrible practice to ever start your engine out of water. I started a new pump on the trailer in the water but the boat wasn't quite far enough back to submerse the pump and after a few seconds with no water coming out of the pee hole I shut it off and backed in farther to submerse the pump and a very weak stream came out. I burned the rubber impellor almost instantly. Be sure the lower unit is plenty deep for the first time starting, the pump won't lift the water even if it is any distance above the water.

[@JesusLove723]

I have a 2000 25hp mercury... This vid was a great help. Thx!!

[@mbeck3132]

Very well done I wonder if it’s the same for a 2002 model?

[@finnanutyo1153]

Im sure itll be thw aame on my 2003 25hp mercury elh. Mine has been running rwally slow for thw past year or more. Pretty sure ita the carb. Im doing a aeafoam treatment, but the water pump crapped out after 1/4 of a gallon of treated fuel went through it. Good thing watee pump kits are cheap

[@oilheating214]

Wow you make it look easy

[@RuXsel]

U remove those 4 big screws like it was nothing.. i have to turn into hulk just to turn those screws 🤣

[@Dave-jc6ky]

Hi, Thanks for the informative video! We have a 1987 Mercury 2 stroke XD ELH outboard. I will need to get this done. I already have the kit. However while apart I also have a complete seal kit and need to get that done and change the prop and prop shaft seals too. There is a single, "plastic" perhaps nylon nut for propeller and I need to find out if it needs replaced each time the prop is removed. Hopefully someone knows the answer to that and if anyone knows of a video on replacing all the seals in this lower unit PLEASE let me know. Thanks!

[@chuckburgess6592]

looks like my job next. thanks for the information.

[@viviendolavidafeliz]

Thanks for your video, I'm trying to get the extractor key for the tail of that same engine and I can't find it anywhere and many mechanics don't even have that key. Can you help me know where I can get that key?

[@ericpigg2689]

Mercury's mess with my head with that weak stream when the engine is cold! First time I changed my impeller, I thought I did something wrong.

[@TheBagman1977]

Same

[@kylemanson3015]

Mine does this too. It has a small amount of water coming from the tell tale when it cold. The tell tale gets stronger as it warms up. Is this normal for these outboards?

[@wmkess]

@@kylemanson3015 It must be tapped into the actual cooling passages, so it is dependent on the thermostat opening. Most outboards have it on the bypass line so it has good flow at any temp and only varies with engine rpms.

[@coleman1994able]

I have this exact motor and mine does the same thing! I thought I might need a new impeller until seeing these comments and this video.

[@cupslinga]

Was told to check the thermostat is moving freely as well, at the water pump change times as these are responsible for overheating the powerhead when they jam shut 👍

[@jimfry5385]

nice video. one question. I saw that you didn't use the 4-bushings. how come? Thanks Jim

[@gloomgloomy9147]

Look very easy now ! I have a question... I just bought a Mercury 25 hp 2 stroke and I can`t visualise how is attach the throttle barrel, the engine is a second hand, and I`m not sure it missing maybe a piece. Can you show me with a short video how this is attach ? I have the Quicksilver control. Thanks in adavance.

[@leonarddutra1739]

my mariner has a strong stream also down shaft to lower unit

[@suzanveltre7015]

I was forced to choke down a Harris ad to watch this video. Seriously dude?

[@ShnitzlHaus]

……… 🤷‍♂️ I don’t choose the ads displayed.

[@goneFishing-yx5zy]

I just did one today and notice water coming out of where the shift rod comes through the that gap right about the lower unit dose yours do the same

[@georges947]

Thanks for the reply I'm thinking is good looks the same at the end of video it's been sitting since 2005 just picked it up and going though it. Thanks.

[@jacksonjuergens597]

Thanks for the help good vid will subscribe

[@user-mx8gy7gl5g]

Hey dude loved the video great help I’m not much of a mechanic. But I do have a problem hopefully you can get back to me. Put everything back I believe correctly except I do not have forward on my motor what did I do wrong?

[@Ethan-tz4kp]

Does anyone know about how long this would take for someone whose never done it before with decent mechanic skills? Thanks, the video is awesome and giving me the confidence to maybe try myself!

[@jeffreyotten7020]

2 hours from start to finish. Did it yesterday.

[@shaneodom6574]

Just curious I lost the washer on the shift linkage. Should I go-to my dealer and try to figure out what size? Or can run with out it? Oh I have a 1988 25 horse mercury. Not even sure if it came with one

[@huntmasterjames]

Do those reed valves got bad. I been having trouble keeping my 25 hp mercury running. Carb rebuilt. Replaced vacuum lines.. getting gas out of vacuum lines when suction applied. Any suggestions.

[@MrAndreisousa]

hi thanks so much for this video, if I do everything correctly and still no water coming out in that same spot, that means there is a blockage somewhere, any ideas how to fixed it? thanks in advance

[@socalinhouse]

excellent video dude!

[@ShnitzlHaus]

Thanks!

[@enercaledonie8496]

Merci pour le partage de nouvelle caledonie 😉👍

[@davidv7616]

Great detailed step by step thank you I just did mine today

[@rustybill8702]

This was the best instructional video I’ve ever watched. I wonder if you might tell me where you found the model # location? The serial # on my 25 hp 1994 mercury was easily found but not the model number.

[@30383]

If your motor only has a plate showing the serial number (older models), Mercury has a web site where you can put in the serial number and the year and model number will pop up! It was the only way I knew how to order the correct impeller. Great video, by thye way

[@badluk1]

Great video!! Thank you!! (And still scared to try it lol)

[@Dave-jc6ky]

My motor is a 1987 Mercury 2 stroke and requires an o-ring seal near the end of the driveshaft. It wasn't on mine and I'm wondering if it came off during removal of lower unit and remains inside of the driveshaft housing. Do you happen to know how to remove the driveshaft housing so I can check for the o-ring?

[@leemcguire7436]

What happens if when I pulled my lower end I didn't have a washer on the metal rod.like the one u said not to lose

[@gardeningGTA]

I have the same motor but with electric start. I can start the engine. But the engine bogs out and stalls after I press the accelerator. Any tips , ideas what the issue might be ?

[@josephberlin5987]

Great tutorial. Seems a lot fewer steps than for omc

[@ajfarr3369]

Should the water tube on my 2003 mercury 25 HP have a snug seal at the top end ? There is a lot of space at the top around the tube .

[@LeslieWorks]

A bolt just snapped off inside when trying to take the bottom off....now what?

[@LeslieWorks]

Got the other 3 off and it dropped, but the washer didn't come out 😂

[@joeblowjohnny2297]

Everything is remove 4 bolt and shifting cable is remove but my 25 mercury foot still won't pull out . It's moving slightly but won't slide out . Even trying to slightly bang the foot with 2x4 . Slightly moving but won't pull out . What do I do ?

[@shanehester4852]

Do you know if these motors have a temperature alarm or not I have a 1998

[@JoshVanHoose]

Well done!

[@jameswhitman2240]

Thank you for the very helpful video. Can you offer some additional guidance and some trouble shooting. I replaced the impeller on my 4 stroke Mercury 30HP of similar vintage to the motor you work on during video and followed the steps carefully. After I got the engine put back together with the new impeller and restarted the engine, it doesn't make water fully. There is just a bit of water coming out of the outflow and it looks like water is being pushed up from the lower unit but outside of the lower housing. It appears as though only some of the water is making it to the upper section. Where would you start to diagnose where I may have made a mistake?Thanks

[@ericremillard8335]

What is the point of the little washer on the shifter part? I changed mine but it didn't have 1. I bought it used tho so the owners before me might of lost it ?

[@tbtactical]

I have gas dripping down from between the prop and skeg. Any idea what's going on? Boat will turn over but won't continue running. Also, great video! Thank you!

[@ShnitzlHaus]

Exhaust runs past the inner prop. Normal. If allot of raw fuel it’s rich. If just oil normal. Hard to tell without seeing.

[@sewing1243]

The idiot engineer/designer or whoever in procurement decided those two SS machine screws holding the carb cover on should have hex heads, not Phillips head or allen key head, should have to go and remove every cover on every engine ever sold in that configuration and replace them with a user friendly screw. I found that a 5/16" Craftsmans nut driver, if really held tight against the head of that bolt will allow them to be removed. I didn't have a metric set of nut drivers so I can't say if an 8MM nut driver will work.

[@dylandavis4074]

Do these 25hp models have a thermostat or should they be pumping water immediately when running?

[@Asys1985]

I changed impellar and mine is leaking water out from the area just above the water level. Alittle bit above the lower stream you have. Any idea what it can be? I get a stream up aswell and its alittle hot so you can atleast touch it without getting burned.

[@MrGabys91]

My water tube stayed inside, it didn't come off. The water tube seal (the rubber piece you referred to) stayed attached to the housing though. I have a 94 merc 25 hp 2 stroke. I didnt hear anything crack, everything came out smooth. Is mine just like that?

[@markbaldwin975]

Great video...very thorough and detailed.

[@ShnitzlHaus]

+Mark Baldwin :).

[@kenhart5259]

What's so important about the washer? Mine didn't have one

[@ksemi02]

Very informative, I’m doing mine now. But my kit came with two the paper gaskets, did yours? Thanks:)

[@Dave-jc6ky]

HI, Our 25 hp 2 stroke is a 1987. It look similar in design though the part to disconnect shift shaft is a bit different. I understand on mine there is supposed to a washer on the shift shaft to you have to be careful not to lose when dropping the lower unit. Is there something that insures on yours the washer doesn't fall off inside the motor when you drop the lower unit?

[@connorjacob4339]

I think I lost mine and I haven't put it back together yet do you know what it's for

[@larryhauck3285]

Fantastic video!

[@RubiconUnlimited]

this install is Water Tight! great vid

[@RossWoodward-sg7ni]

Clear and concise thanks!

[@smallflipz2302]

I need help i cant get the shifter rod and the clip to line up!! Everything was put back the same

[@mauriciodiaz1310]

Why is it only trickling small amounts of water ? I have same motor except a 20 hp and its doing the same thing should i be concern please help me???

[@ShnitzlHaus]

It should have a thermostat so if it’s not up to operating temperature it will trickle out. Mine opens up when warm and has a solid stream. But being online and not in person I can’t tell forsure. I’m in fresh water so I don’t have bad corrosion

[@michaelfelices4669]

Hola buenas tardes, quería saber que sale los cables del baston o acelerador de ese mismo motor mercury 25 hp. Tengo el mismo motor pero no logro conseguirlos

[@ZoutdoorZ]

What is that bolt on the bottom on the lower unit by the hydrofoil ? You can see it at 7:20

[@poopyhead20002]

Would you be able to tell me when the fuse is for the electric start?

[@samlancaster6767]

What is the hole in the lower unit just above the water line that’s shooting out water? I just replaced my water pump and noticed mine was doing that.

[@samuellorette5708]

Thanks a lot! Will be very usefull

[@lel7788]

Thanks A LOT, it helped me :D

[@riverrivers250]

Can a totally broken water impeller cause the engine to lock up?? Since its right on the drive shaft,,,, cause mine was in pieces inside the water pump housing.

[@ShnitzlHaus]

Possible pulling by hand. Running….. I suppose

[@riverrivers250]

@@ShnitzlHaus okay… jus wanted ur opinion.. i changed my water pump and drove arnd for 2 hours full speed. Didnt die on me…. Everybody was telling me my motor is “finished” and “it wont run long” but idk…. Gonna go for another test drive

[@jasongodmaire7552]

So I don't have to drop the oil in the foot. Good to know. Would have done it for no reason

[@vdwalrw]

Great help thanks!

[@ryanmiller5115]

I’m new to my Mercury 25. I’ve had Yamaha before. I’m just checking but my water stream is really weak like yours after the pump replacement. Is that the normal output? It picks up a little opening the throttle. But not a hard steady stream like my Yamaha. Is this normal?

[@dhajek2754]

mine does the same thing. I think it has something to do with the thermostat.

[@papazoo1]

Nice detailed video, I just bought a boat with a 97 mercury 25 HP, and was concerned that I may have a bad water pump because it didn't have a good steady flow of water. It will go between a good steady stream to sputtering out just a small amount. I notice yours look the same, is this normal. I haven't put in water yet just using muffs. I was told it was service with new impeller, but was thinking about putting a new one in to be on the safe side.

[@ShnitzlHaus]

If you have a thermostat that will be a reason for the sputtering stream. I haven’t had allot of success with muffs as of now. Try a garbage can full of water, rev the engine slightly out of gear. It should warm up enough to make a constant stream. I doubt your impeller is shot, but it’s good to be cautious.

[@papazoo1]

Thanks you for responding, that as fast. That makes sense about the thermostat will try the container method also. Look Forward to viewing your other videos.

[@jonathanb9429]

Excellent video ! Thanks

[@randallwharrell]

Great video. At 3:36 you talk about that washer. What is the function of that washer? Also, when I dropped my lower unit, the drive rod and spline rod came all the way out. But the other rod (I’m thinking it’s a pipe that uses water for cooling. Should it come out when removing the lower unit?

[@ShnitzlHaus]

I can’t recall the washer. If it supported the rubber when shifting on the upper head side (engine). If the pipe doesn’t come out that’s okay. When assembling it’s better to have the pipe in first because it’s near impossible to tell where it’s going when it’s installed on the pump first. And if it doesn’t engage the engine above you will not have cooling and will need to drop the lower unit again.

[@tonyfarr7397]

The washer fell out when you re o ed the lower u it ! Look for it on your video