15hp - 18hp tear down two stroke.

[@ct1762]

these Tohatsu's are the most ingeniously simple motors i've ever worked on recently. Had one torn down in 25 minutes! the ingenious parts are small, but extremely smart. for example: the crank case half has recessed dimples to put a screwdriver in to pry it apart without damage. 90% of the screws are 10mm. the ignition is mounted in a modular way, with an absolute minimum of fasteners. i could go on and on, but these are such a joy to work on. minus the crappy paint and corrosion issues.

[@25hpboatracerman]

Agree totally mate 👍. Cheers 🍻

[@932359]

Hello, Master Tohatsu 😀, In 2009, I acquired a Tohatsu M18E2. I’ve used it in saltwater, and I estimate the usage to be around 800-1000 hours. During this time, apart from routine maintenance such as spark plugs, lower unit oil, and impeller rubber, it never gave any trouble and always delivered good performance. In fact, when I cleaned the carburetor after 14 years, there wasn’t even a speck of crystal apart from a little residue on the lower tray. By the way, I live in Istanbul, Turkey, in Golden Horn. This summer, however, it started having idle issues! I checked the spark plug, spark plug wire, and coil, cleaned the carburetor again, but nothing changed. Eventually, it became hard to start and began stalling at idle... When I measured the cylinder pressures, I got a result like 75-125. On top of the high costs you mentioned, we’re also having trouble finding parts in Turkey, as it’s an older model and parts are hard to come by. If I can find the parts, I plan to do the overhaul myself. The engine is currently in my garage, and while removing the cylinder head, two of the bolt heads broke off, and the other bolts were heavily corroded... Even though it’s a relatively simple engine, I came across your videos on KZbin while researching if there are any fine details to be mindful of during the overhaul. Your videos are fantastic and very explanatory, thank you for that! If I can source the parts and continue the overhaul process, I’d like to consult you, Master, in case I get stuck-of course, if you’re willing to help! That’s my Tohatsu story, which led me to meet you. Thanks again for responding to the previous comment. Take care, Anzac King... Greetings from the old world 🇦🇺🤝🇹🇷. Oh, by the way, I love rakı 😀🍻 cheers. P.S. Whether the corrosion seen in the video is a result of normal use or if it happened due to an incident like falling into the water?

[@25hpboatracerman]

Mate, sounds like you’ve had a good run with that motor 👍. Can you get the parts online? I would check that the bore isn’t scored before ordering too many parts though. I have a video on removing broken bolts (actually an 18hp block) on my channel if you need. You can contact me through these messages champion. Cheers 🍻 Aussie Boat Guy 😎

[@jaspersoda8286]

Thanks heaps for your videos. Clear, succinct. Did my first Tohatsu carbie strip down and re-build whilst suspended off the back of a Cat at anchor based on your instruction. Engine is now running like a dream. Legend.

[@25hpboatracerman]

Thanks mate 👍 I really appreciate your comments. That is the exact reason I do those videos and glad your motor is running sweet again. Cheers 🍻

[@aaronbouckaert6023]

Thanks for the video, good detail and explanation of the tear down and tips for storing bolt etc.

[@932359]

in this video you dismantled the motor but i couldn’t find a video that you reassamle the motor. Is there a video that you reassamble ?

[@25hpboatracerman]

Hi Champion, I am unfortunately still looking for a genuine crank, new ones cost a fortune. Cannot bring myself to use a cheap aftermarket one. I did a video titled outboard rebuild where I rebuilt a 9.8hp which is so similar to the 9.9-15 and 18 that it would be pretty much the same video. That video should get you out of trouble. Cheers 🍻 Aussie Boat Guy 😎

[@bhishamramesar8571]

I have a mercury 9.9 hp (year 2003). Can that be converted to 18 HP?

[@25hpboatracerman]

Hi Champion, If you look on my channel I have a video comparing the 9.9hp, 15hp and 18hp and the difference. Cheers 🍻 Aussie Boat Guy 😎

[@932359]

Hello master I need your guidance. For the Tohatsu m18e2, the cylinder head bolts are m8x40. During the tightening process, what torque do you apply with a torque wrench in newton-meters and kilograms? 🍻

[@25hpboatracerman]

Hi Mate, I torque the 8mm to 18.1 ft pounds and 6mm to 6.5ft pounds. I would definitely check if this is suitable for your motor. Cheers 🍻 Aussie Boat Guy 😎

[@aidencronje736]

where can i get a parts manual for a 4 and 5hp 2 stroke mercury

[@nerd1000ify]

Do they use some kind of sealant between the crankcase halves? Also I'm guessing the crankshaft must be pressed together from two pieces. Otherwise there wouldn't be any way to assemble that middle bearing onto it.

[@25hpboatracerman]

Hi mate, Yes there is a crank case sealant that is used between the halves. The cranks are pressed, actually a fair few parts pressed together to make the crank. Cheers, Aussie Boat G

[@jamescameron24]

love your videos man, just wondering where your located and have you got parts cheers

[@johnstevens1192]

Gday mate. That tohatsu is exactly the same as my 15hp Mercury. Is there any way to put an electric start on these? I have a buggered back that makes pull starts challenging sometimes.

[@25hpboatracerman]

Hi Mate, Yep the Mercury is made by Tohatsu 👍 Yes you can put electric start on it, I put it on my one 😁. I think they sell a kit on eBay for it or you can call around the local outboard wreckers. I got mine off another motor that was cooked. You need the flywheel with teeth, starter, charging rectifier, starter solenoid etc etc. It’s an easy thing to add. Cheers 🍻 Aussie Boat Guy 😎

[@qldshane]

Hey, great vid. Where do you /can I buy a decent set of compression gauges? The Supercheap and Trade Tools brands don’t work. Thanks

[@25hpboatracerman]

Hi mate, I got my current compression gauge from Gasweld. cheers

[@hselman9837]

What causes it to lose compression

[@25hpboatracerman]

The rings on the bottom cylinder are not sealing against the bore walls. Water ingress caused it in that motor, other motors can loose compression due to an overheat it no oil in the fuel if it’s a two stroke.

[@zanebaker4848]

What’s different between the 15 and 18 mate

[@25hpboatracerman]

Hi mate, I actually did a video on that exact question 👌 If you search my videos you will find it, I have the blocks on the bench and run through all the differences. Cheers 🍻 Aussie Boat G 😎

[@BICPROCESS]

Bonjour j’ai des petit problème avec mon 15 pouvez vous m’aider ? S’il vous plaît

[@25hpboatracerman]

Hi mate, Unfortunately it’s very hard to diagnose a problem without actually having the motor in front of me. Kind regards, Aussie Boat Guy 😎

[@BICPROCESS]

@@25hpboatracerman my problem is that I put on the gas but the engine does not accelerate, I would like to know if it is the carburetor or the CDI, before it was slow but after changing the piston and connecting rod bearings it is getting worse the mechanic tells me that it is It’s the CDI that’s starting to die

[@pieropower1260]

Love your video’s mate, I hope to get a fish nipper like you have with a very similar set up👍🏼👍🏼🇦🇺🇦🇺

[@BP_Editss]

Hey mate, what did you do to fix it and to get it running properly?

[@25hpboatracerman]

Hi mate, Luckily I have a few good second hand parts for those motors. Used a good crank and pistons, another good block, new seals, rings and gaskets. Proper run in and she is sweet 👌 It’s always disappointing pulling down a motor to find that much damage, on the other hand when you pull one down and it turns out to not need too much it is great 👍 Cheers Aussie Boat Guy 😎

[@smelmore]

im still looking for a 9.8

[@25hpboatracerman]

Yeah, getting hard to find a good 9.8hp, great little motors.

[@SoundzAlive1]

I have a Yamaha 9.9hp. In Rockdale area. André

[@ct1762]

ive got a 15, 18 and 9.9 all short shaft accept the 9.9hp which is 20'' (little longer on Japanese motors) for sale. the 15hp is the one you want. same weight as a 9.9. the 18hp is a 300cc monster that puts out about 21-23hp at the prop!

[@smelmore]

misso made me pass one a while back

[@seriksson9721]

Are Merc and Tohatsu the same engine?

[@adventuredownunder2131]

Yes

[@smelmore]

broken key my guess wave jumping

[@25hpboatracerman]

Probably, also would make sense why it was swamped. That’s how I received it unfortunately. If it was swamped I just wish they would have run it for a few hours to burn the water out. Cheers 🍻