Outboard Lower Unit Troubleshooting | Outboard Engine Lower Unit Issues | Boats.net

Dealing with lower unit issues on your outboard? In this video from Boats.net, John will take you through some common lower unit problems and where you might look for the cause. Faulty seals can be a common cause for lower unit problems, and we’ll take a look at where those problems can originate.
We’ll also tell you why a grinding noise coming from your lower unit might not have anything to do with the unit itself, and what you need to check next.
See how a lower unit works on an outboard: • How an Outboard Lower ...
See the lower unit diagram for a Yamaha F225 here: www.boats.net/catalog/yamaha/...
Read how to do this step by step: www.boats.net/blog/troublesho...
VIDEO HIGHLIGHTS
Crunching noise - 0:30
Fluid contamination and seals - 1:35
Engine overheating and water pump - 3:30
Can’t remove the lower unit - 3:50
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[@GreatTutoring]

Excellent video. One of the best and most informative that I've ever seen. Thank you!

[@TheBluceRee]

Insanely helpful videos.

[@mauroalvarezsi]

This guy is awesome! Works on ATV’s, SXS’s, boats, etc..

[@myotheraccount5947]

The more I learn, the more I realize I really don't know much, but I'm learning. Thank you

[@corybell1255]

Dude you are awesome.. Great video

[@Gus10101]

This is a great video and advice! But the best part were how you so cool you looked taking the glasses off @ 3:32 into the video lol :)

[@louieyoung3716]

Yeah can you show a video of how to assemble a 150 horse Johnson outboard motor lower unit

[@TheDuffman1986]

Brilliant information, my engine wasn’t going forward, just into neutral and reverse, took the gearbox apart n fixed what I thought was the problem but after assembling it back it now goes into neutral and forward but not reverse, I’m starting to think it may be something todo with the shift shaft?

[@nf5557]

Thanks for the Great videos. I had oil leaking out of my water intake and pressure tested my lower unit (2007 115 Mercury EFI) and did not see any bubbles at the seals but heard a leak from inside the water intake. Any ideas what it could be? is this the inside seals?

[@richieperez21]

Great video! Once you find water in the lower unit, and replace all seals and gaskets, is there something you should do to the metals before assembling and adding gear lube? Some of the moving parts seems stuck or rusted. Transmission was working fine before discovery of water, did not blow up or break anything yet.

[@pino_7428]

I replaced the bearings because those were the ones that have rust.

[@kegman1]

Can you do a video on adjusting the throttle and shift cables?

[@jenniferallmon3681]

Agree. Please make this video.

[@pino_7428]

A month ago I started to drain the lower unit fluid and boom! First thing that came out was clear water following by the gear case oil. Technician needed to replace all seals.

[@bouldernelsonbigfoot]

good vid

[@marconoahu2]

One thing everyone should know is the shift control has to be worked into a little space so the locking mechanism can hold it in place. Raise the motor up and look with a flashlight where the shift control rod passes up through to where it is linked. You have to adjust the lever nail it s position perfectly in that slot before you can lock it n places took me an entire day fiddling it around. It wasn’t until I used a flashligh5 so I could see where the rod is actually position so I could slide 5he lock pin over.

[@pierreperreault7801]

Hi john Pierre here in BC have a question here trying to press our the roller bearing that’s inside the f90 gear in the leg Do you press on that thick stainless washer to push it out hope you could answer this no one around Bc could tell me thx your the man

[@shannonfishkill8957]

I really wish you would’ve went over the main shaft seals and shifter seals my outboard I believe is leaking from the main shaft seal under the impeller please do a video showing how to change these please.

[@sgray1906]

Is the new Mercury prop shaft outer seal suppose to cut string ? Looks like it might.

[@seanjordan5635]

i appreciate the great info! I have a question: i rebuilt a mercury 250 lower unit (torquemaster).The main shaft is difficult to turn by hand when I tightened the retainer nut on the top bearing. the impeller has not been installed while attempting to turn. should I add more shim material under the bearing casing on the top bearing to relieve pressure on the bearing? not sure if it should turn easily by hand without the impeller installed? thanks in advance

[@Farmer2492]

Hi great video just a question i have a 210 Quintrex legend center console boat with a 60 hp Mercury engine i think its a bigfoot its hard to shift in to gear i have taken control cables off and it shifts smoothly so must be at the engine end any ideas i can do to make it change smoother thank you

[@danielboles6263]

I recently purchased a lower unit impeller kit from you ,I have one question,when I put the lower unit back up into the power head I had the unit in neutral, had a bit of trouble getting it back in but I got it, but I did notice a slight gap, about 1/8 inch between the lower unit and the bottom of the power head ,is that common , or should that be flush with top and bottom with no gap at all?

[@tricialchaney1546]

Any thoughts on this - I was at about 3,500 rpm hit a decent size wake and afterward found my starboard outdrive clicking. The more I rev it the louder the click. We idled back to the ramp, after pulling the boat out I shot this video: oh well, couldn’t share the video but when spinning the prop back and forth (in neutral), it has a loud clank much different noise than my port side.

[@SouthPawBrown]

Do you have any videos or advice to fix an issue with my 2 stroke motor slipping back into neutral when i start accelerating faster? Thanks in advance.

[@nathanielnewsome6699]

mine has been shifting into gear great until the other day I went and it wouldn't go into forward or reverse any suggestions about why I took it apart and all gears look good no wear on any of them

[@wazup3333]

he said if you pressure test it and there are no leaks then you need to pull the bearing carrier.. but why would you pull the bearing carrier if there are no leaks when pressure testing it? how can water get in if there are isnt a propshaft/driveshaft leak?

[@garysicard7199]

I have a alpha one gen 2 and was wondering should I have any vert play up and down on the lower unit shaft? also as I turn the shaft i hear it clicking inside till i turn the shift lever not engaged either forward or back but as in a neutral position. the unit is from 2021 and maintained. last thing why does water come out in a stream out the little hole from the right side of lower unit between the fin's? thatnk for any help!

[@christhorbelch3589]

Had a guy put new water pump on and propeller now when I slow down off of plane I hear a clanking sound never heard it before when I turn the propeller back and forth sounds like something hitting the sides inside of unit

[@Veemack21]

So I can run my motor with muffs or in a large container of water an it runs when I put in the water aka the lake the motor will not stay running? Any ideas ?

[@melcase791]

do you have video on Mercury? I have a 1997 V6 150hp. What gear should engine be in at lowering and then at install?

[@luidangel2]

Mel Case neutral

[@juanluismedrano7132]

What can I do if the propeller doesn’t spin (by hand) to one side. I can turn it one way but not the other way

[@user-kc2ig8ik4y]

Hi there I had a 2003 mercury 60 hp 4 stoke i has a problem is when I run on land the rpm can go up to 6500 , but when I put it in the water a engines can go up to 4000 rpm only , so can you let me know what wrong with it , thank you

[@yum4906]

When i put in forwrd gear, i spin the propeller but flywheel not follow it. Just Clicking sound. But if i spin backwrd in forwrd gear the flywheel is folow. Why?

[@TheSilverSurfisher]

Will a lower unit issue cause the outboard two stroke engine to lock up and not turn all the way over??...(I get one click when turning ignition key and starter gear moves up to flywheel gear (that’s on top of stater) and is trying to engage but engine won't crank or turn over to fire up).

[@warrenlouisiana2277]

Where & how do I adjust it to stop the grinding

[@catchnc4131]

I hit a stump this morning and it came out of gear now the prop doesn’t spin in forward or reverse when I rev up it spins freely by hand though any ideas?

[@marshalllee4873]

The prop seal at 2:22 is in backwards....

[@wtfjpgmailcom]

How a bout when it chatters only when it's in gear at lower rpm

[@joerillarilla8524]

.53 linkage..get to the description on the video. I have a 6 hp that under a load only on top end it does a strange slip and it's not the hub I am pretty sure is a worn gear.if it was a slipping prop or hub it would spin out..I wish it was just the prop or hub of the prop..this is a eternal problem. Just wanted a second opinion. I will try and post a video thanks much everyone out there. I am a Yamaha man myself. Diesel even better while we're at it lol

[@armandorodriguez9668]

my boat just stop going forward but the propel works fine when Im going in reverse what do you think should I look first??

[@teamslaiyans3808]

Im the opposite, mine can't reverse but can go forward, lol..

[@ZoranBerntsson]

great video. i had my friend help me change the impeller on my parents old yamaha 9.9d 1990ish 2 stroke. we were working on the motor trying to get the lowerunit loose for 2 days... the driveshaft was stuck under the motor so we had to use lots of force to get it loose. after the impeller change it started to make a semiloud high pitch noice that follows the revs in volume and pitch. its louder when in gear and high throttle. gears are going in smoothly. there is no water in the oil. installed it back with lots of lube. good cooling. works great. got power. after the first trip the high pitch noice was abit lower in volym. my fear is that we have separeted some gears or something abit. and that it will damage the engine/lower unit in the long run. i dont know much about the finer details of boat mechanics sadly. anyone have any guesses?

[@michaelhipp6632]

I have a 95 force 40. They dont make parts for. I need lower unit gears.

[@luidangel2]

I’m working on a 1985 Black Max. It won’t pump water up to the engine even after replacing the entire water pump. Any suggestions?

[@steveo201]

There’s blockage somewhere inside the motor look up your motor and see if you can figure out where to dig sometimes just putting screwdriver in pee hole helps

[@jimmyadams9257]

I have 1987 Yamaha 70 hp I have a newly professional rebuilt lower unit having with the adjustment with forward to reverse any help thanks

[@johnnyricks5919]

I'm having trouble with my 2001 90hp tracker motor I put a new water pump in and now my shifter is all missed up and I cant seem to get it back in to the right pattern can u help me

[@shannonfishkill8957]

Yeah I wish they would do that to they don’t seem to respond to any questions this video didn’t even address the shifter seals or the main shaft seals under the impeller.. he spent much more time talking about how to get the foot off … I also commented with a question and got no response

[@shaneprescott432]

Hi I have a question: im working on a yamaha sterndrive . The lower drive is off . The unit doesn't free spin in the direction it should as per manual. Prop shaft spins nicely in neutral. Removed the prop shaft and checked all gears spin free . And all good . Now I checked all needle bearings and all good. I examined the shifting unit that mates to the shifting slide. It's not new but looks as it should function with the shift cam rotated by shift rod . Taking the clutch dog off and removing the slide: I see the detent balls and set them in my tray . The heavier spring I noticed there is not much movement ; like the coils are collapsed. This spring seems to be intended to push on the clutch dog pin and it does, but nothing significant. ..... I thinking this is a possibility. The other thing I see is there is very little ramp machined on the non engaging sides of the clutch dog . Any thoughts?

[@joshyingling]

Should have watched the video before tearing apart my lower unit. Lol