Replacing the impeller and gear lube in a Tohatsu four stroke 3.5hp outboard engine 

These videos demonstrate how a simple service can quickly become somewhat complicated. This may lead some to avoid DIY but those who pursue the task have everything to gain in increasing their comfort and familiarity with their machines. Well done and thanks!

Great easy to-follow and clear instructions. Much appreciate the time taken to create this video.

Thank you John for making and posting the video, I changed the impeller on my 6hp Nissan and this was very helpful

thanks for the wonderful video. I really enjoy my 3.5 on a small com-pac sailboat, and will need to do my own maintenance to get the most use out of it. I'm saving this to my library!

Thank you so much for this video!! I am inspired by your video, and will be changing it myself.

Thanks this was very helpfull for me 😊😊

Good work 👍, thanks and best wishes!

Thanks this was very helpfull for me

Merci steve, une vidéo très instructive, je ne m'attendais pas à un travail si complexe avec le bas du moteur et la pompe. translate by google: Thank you steve, a very informative video, I didn't expect such complex work with the bottom of the engine and the pump.🙏👍😎

Having fought one of these many times, I suggest the following to make the replacement of the leg easier. Tip. mark the position of the gear change clamp behind the grommet hole -before undoing it- this is critical! I use correction white paint. First, remove the engine from the boat and empty the tank. Fit the engine transom clamps with an 18" length of 4" x 2" timber and clamp the engine upside down in a vice. Even horizontal is easier than down. Then tighten the steering clamp. Using gravity makes it so much easier! A small LED light is essential, together with a couple of short lengths of 3mm welding rod bent into a 'U' shape at the end, to hold the water tube and gear link clamp in place whilst sliding the shaft into the spline in the engine. No resistance should be encountered if it's in the right place in the splines. If at first, you don't succeed etc--- takes a bit of practice. One hour should do it!! Have fun-Peter.

Top of the top! Very informative! Thanks!

GREAT!!! This is exactly what I was looking for! Thanks so much for sharing ❤

thanks for a great "honest" video !!!! really made the job easier

Thanks for letting us know 😷🖐🏽🖐🏽👍😁

Thanks very much, very helpful!

Than you, very good video, helped a lot. Pozdrav iz Slovenije

I’ve just managed to split the leg on mine (same engine). I should have done this yearly, it took a lot of persuasion to get the leg away from the power head. The issue was not the drive shaft seized into the head as I thought. It was the steel stud at the bottom seized into the aluminium casting. This only released after quite a lot of heat on the stud from a mini blowtorch and some enthusiastic whacking with a large hammer and a piece of hardwood. (Careful not to break the cavitation plate!) hit it near the front. - also try hanging the leg upside down and spraying a load of releasing lube in there - leave overnight or even longer.

Very informative. You do sound like David Attenborough sneaking up on a pride of lions though. :)

Great video but one thing. Use some silicon o ring grease on the impeller and use the absolute minimal amount. The reason is that while it is all well lubricated any sand etc... will be caught up in the grease and create extra impeller wear.

You'll save yourself a few quid over time doing it yourself Steve. Hope you and yours are all well mate. Let's hope the water will be calling us soon.

Thank you for the heads up on a few of these procedures. I have a prpane lehr that i just purchased used and the lower unit appears to be similar enough to yours. Its nice to know what youre getting yourself into!

Interesting to see how to service the outboard, hopefully not much longer until you can get back on the water.

Really good video easy to fallow step by step. But let me make a comment, all those grease you used on the impeller and the shaft will lend in the water because it is in the way up to the engine cooling channel.

Have just done the impellor task. In my case the splines lined up easily but my clamp fell off, which was a nightmare!

Glad it took you 6 attempts. It took me ages as well All other videos it goes on Frist time. Thanks.

Bravo anch'io oggi faccio il tagliando più la girante

why are you whispering? haha good job. i liked your video and work. helpful. thank you.

IMPORTANT NOTE The water pump is not self-priming! So just covering the inlet holes is not sufficient. THE WATER LEVEL IN THE BUCKET MUST BE HIGHER THAN THE PUMP OR THE IMPELLER WILL DESTROY ITSELF IN SECONDS! Peter.

HiSteve, Very informative video. Can I ask where you sourced all your parts from? I have the exact same engine and am unsure what oil plug gaskets, impellers and anodes to buy? Many thanks Thomas

Is it normal for a small amount of water to come out of the plug where u connect the shifting rod together

Did you actually replace the gaskets on the water pump assembly? I didn't see that part. Is it necessary?

Nice video, well done, buT you have to turn the shaft clockwise when you put the waterpump housing back. Your explanation makes it little bit complicated to understand.

I need to replace the lower oil seal on a similar 3.5 mercury, looks the same as your Tohatsu have you replaced your seal , How do you remove the old seal inside the bearing Rick

Does it also start in forward position or is than a gear save engaged?

Does anyone happen to know the part number for the impeller for this motor? Thank you.

can you share the part numbers for all of the parts please.

That blockage looks like the drill that was making that hole during manufacture did not go all the way through the casting.

Is your video image reversed? It looked like you were turning the drive shaft anti clockwise, but wouldn’t that mean the impeller is folded clockwise?

When you change the oil in the foot if its milky like yours its water inside need a check-up.......the color must be black dark

Pretty much every lower unit of that type that I've seen, that hole is clear through into the gearcase void. I'd say its a manufacturing fault. That oil you removed initially has water in it from the look of it. Hard to see how that gearbox has been properly serviced without that vent being functional......keen to hear the outcome.

Complimenti per il video 🤙💪 ho lo stesso motore e faccio anch'io manutenzione da solo L'olio io l'ho messo togliendo l'elica e poi i 2 bulloni che tengono il tappo dietro l'elica con guarnizione e ho messo la giusta quantità di olio, il mio olio Gear non era bianco come il tuo ma marrone colore dell'olio motore x intenderci

What type of grease is that?

Come mai l'olio non lo entri dal bullone superiore? Così scende verso la coda...o no?

I understood the engine turns the drive clockwise making your impleller blades face anti clockwise but you turned the drive backwards making your impeller blade face clockwise

The grease can not be petrol based because it will tear down the impeller

adding grease to the impeller and housing is the worse thing to do! Grease can accelerate the deterioration of the rubber impeller. That's why you use washing up liquid or a special impeller lubricant. Given the very small parts that could go missing I would not attempt this over decking either. Great to do these jobs yourself but without the right knowledge you can make some expensive mistakes.....trust me, I know :)