Outboard rebuild

This is a fairly comprehensive video instructional to help you with rebuilding any two stroke outboard. The principals in this video are useful for any two stroke outboard build.
Hope this video helps, was a lot of work to edit 😂.
Cheers 🍻

[@kick6925]

Hello, my machine's engine screws are fused with the engine. How can I solve it?

[@25hpboatracerman]

Hi, This is a very common problem, you need to be very carful not to snap them. I use a blow torch to heat the block around the bolt and gently work it out backwards and forwards as you can. If you snap any I have put a video up on his to repair broken bolts on this channel. Cheers 🍻 Aussie Boat Guy 😎

[@riverrat321]

Hi mate, great videos you have! I’m about to try my first rebuild on a 25 Tohatsu that has low compression. Think previous owner overheated it. Where is the most economical place to buy gaskets, rings etc. I’m in Sydney.

[@25hpboatracerman]

Hi Champion, I always get my parts from Coho Marine, they are Tohatsu and Anna is awesome plus knows her stuff. cheers 🍻 Aussie Boat Guy 😎

[@riverrat321]

Thanks mate I will contact her next week. Cheers

[@kick6925]

Hello buddy, I didn’t test the cylinder pressure after replacing the cylinder. How low is the cylinder pressure?

[@25hpboatracerman]

Hi Mate, It varies for each motor, I would check with your manufacturer what your specific compression should be. If it’s has more than one cylinder then they should be within 10% of each other at the worst. normally over 100psi will run on but do check with your manufacturer. Cheers 🍻 Aussie Boat Guy 😎

[@KristianSloth]

Thank you for making this. I'll be watching it a hundred times as I just picked up my new (to me) used Tohatsu M9.8B from the mechanic. The engine makes metallic rattling nose when you rev it - probably a bad piston bearing. The mechanic said it wouldn't be worth it to have him fix it but I'm going to give it a try myself next winter... Are there any of the steps in this video I can skip if I only want to change the piston bearings?

[@25hpboatracerman]

Hi Mate, Sounds like a great project 👍 You will have to follow each step of the video and I hope you crank is in good condition, that’s always my stress when pulling down a motor. Cheers 🍻 Aussie Boat Guy 😎

[@KristianSloth]

Thanks. Of course I would rather have an outboard without problems but that said I am looking forward to the project :) Hopefully the problem is only a bearing but I'm prepared to get a new crankshaft assembly if I have to. Someone was nice enough to send me the service manual which should be a great help. Does this sound about right: Tools: Torque wrench for bolts, maybe torque wrench for flywheel nut and an impact driver looks like it's nice to have. Any other special tools I need? Parts: (Obviously I need to replace the damaged parts) Gaskets, oil seals, maybe thermostat. You put in new piston rings - is that necessary if I'm not replacing the piston heads? Other: Flange sealant, non-silicone based gasket sealant and some removable thread locker for the stator screws.

[@riverrat321]

Hi mate, any tips on how to tell if new pistons are needed and how to tell if honing needed vs boring out cyl needed? You have great content on here.

[@25hpboatracerman]

Hi Mate, thanks for your comments 👍 You will know if you need to bore out if you have scuffs in the bores that are deep enough to affect the compression ( most scratches). You will need new pistons if you can visually see damage on the original pistons like scuffed sides, scratches or the ring gap is damaged in some way. If you do need to oversize a bore then you will need an oversized piston and rings for that bore. You will need new rings if your ring gap is larger than factory tolerances (sounds hard but truly super simple) check some of my rebuild vids and I show how to check ring gap. You will need to find out the min and max recommended ring gap for your specific motor and place each ring in the bore it will be used in and check the gap, too big then replace, within tolerance then ok. Cheers 🍻 Aussie Boat Guy 😎

[@seriksson9721]

Everything is appreciated, please post more.

[@25hpboatracerman]

Thanks so much for your encouragement mate. I will keep the vids coming. Cheers 🍻 Aussie Boat Guy 😎

[@CaptainBlackbeard-hx4st]

As already said by many the video is much appreciated! I've the same 9.8 about to do the same. I'm interested in the performance mods to the reed valve etc. Can you share at all or pass on where to purchase ungraded reed? Thanks again

[@25hpboatracerman]

Hi Champion, Thanks for your encouragement 👌 I modified the reed cover myself and it still has the factory reed petals. Cheers 🍻 Aussie Boat Guy 😎

[@Maupie-hp3bh]

Such a cool video man! I have an old Tohatsu from 2003 that looks almost identical, where did you get the gaskets from?

[@25hpboatracerman]

Hi Mate, Cheers 🍻 yeah that would be the sand motor, I got my parts from Coho Marine, they are a Tohatsu dealer. cheers 🍻 Aussie Boat Guy 😎

[@1Chosen247]

I am trying to rebuild my f150. Anyway to contact you regarding some questions I have?

[@25hpboatracerman]

Hi Champion, At this stage I do not have contacts set up, I am in the process of getting that sorted. Cheers 🍻 Aussie Boat Guy 😎

[@kalebsheridan9017]

Did you have the cylinders professionally refinished? Or DIY?

[@25hpboatracerman]

Hi Mate, I just cleaned them up myself. Scotchbrite (the green dish cloth with a slight texture) works well. You just don’t want to scratch them. Cheers 🍻 Aussie Boat Guy 😎

[@boatsail1]

been watching and rebuilding a Tohatsu 6 hp. the 70 and 80 foot pounds of torque scare me. Seems like I'll be striping out the alumn with over torgue. Do you do the 80 pounds on exhaust plate and 70 on recommended areas? Just asking. Your stuff is a big help.... Bill

[@25hpboatracerman]

Hi Champion, Please do not torque your small bolts to 60 - 70 foot pounds 😢 you will snap bolts or strip alloy out. I will get back to you with Tohatsu torque guide on bolt sizes but I think you may have foot pounds confused with inch pounds. Talk soon Cheers Aussie Boat Guy 😎

[@boatsail1]

thanks much @@25hpboatracerman

[@brendanbarker2095]

Dangar Stu would be proud of you!

[@25hpboatracerman]

😂😂 I hope so mate 👌 Cheers 🍻 Aussie Boat Guy 😎

[@siulajonah4438]

There's a black plastic round wassa and a half wassa.where are they located under the grand shalf or uper?

[@25hpboatracerman]

Hi Mate, You can follow the video or check out sone of my disassembly videos if you have a slightly larger motor. I’m not that sure what your asking, if you mean the Large black seal, that’s normally at the bottom of the crank and sometimes the half moon thing goes on one side of the bearing to hold the crank assembly in place. Cheers 🍻 Aussie Boat Guy.

[@darrenclark9776]

what kind of paint did you use on the powerhead? that black looks thick and durable.

[@25hpboatracerman]

Hi Mate, Through the years I have tried so many paints ranging in price. That paint (believe it or not) is Squirts quick dry gloss black (by White Nights) bought at Bunnings straight off the shelf. I have found it super good with great coverage plus a good finish and lasts well. Cheers 🍻 Aussie Boat Guy 😎

[@enaliospearfishing]

quick tip if you want flat surface get a glass or a mirror!

[@darrenclark9776]

dude.......this is brilliant!

[@25hpboatracerman]

Yep, good point and should have mentioned that too. Cheers 🍻 Aussie Boat Guy 😎

[@25hpboatracerman]

Glad it is helping cheers 🍻 Aussie Boat Guy 😎

[@reddragonangler6136]

Gday from Wales UK. I love your videos, they are very informative and you explain them well. I am in the process of rebuilding a 2003 Tohatsu 3.5hp 2 stroke motor. I will be replacing the piston, rings, gaskets and seals, which I'm still waiting delivery of. My question is: Why did you use the Loctite crankcase sealer on the crankcase, and then use the other gasket sealer on the gaskets? is it necessary to use both compounds? I have Hylomar Universal blue gasket and joining compound which is non setting, will this be ok to use to join the head to the block and all the other gaskets please?

[@25hpboatracerman]

Hi Mate, Unfortunately I’m not familiar with that product. The head gaskets normally come with a coating so you don’t need to use sealant (check you one though). The crank case halves are metal to metal contact so a crank case sealant is advised and also you don’t want a thick seal there plus crank case sealant actually sets up to a point. I guess check your product and see if it’s suitable for both applications. Cheers 🍻 Aussie Boat Guy 😎

[@reddragonangler6136]

That's just what I wanted to know, thank you. Please keep the videos coming

[@reddragonangler6136]

Hi mate, which way around do you put the bearing seals on the crankshaft? is the flat side facing the inside or the outside of the bearing?

[@25hpboatracerman]

Hi Mate, I always install them the way they were taken out. It depends on what motor you are working on too, I have seen them different ways. On Japan built tohatsu - Mercury they are often flat side to the top at the top of the motor and flat side to the top on the bottom of the motor too. Which make and hp are you working on? Cheers 🍻 Aussie Boat Guy 😎

[@reddragonangler6136]

Hi ABG, It's a 2003 Tohatsu 3.5hp 2 stroke single cylinder which I'm rebuilding from the crank up. When I took the 2 bearing seals off it looked to me that one flat face was facing the bearing, and the other one the flat face was facing away from the bearing on the other side of the crank which I thought was strange. Also do you know the torque settings for all the powerhead and cylinder head bolts, I've looked in the service manual but it doesn't specify?

[@Howarda1212]

What parts do you have for the rebuild?

[@25hpboatracerman]

Hi Mate, Not sure what you mean but I used all the needed new factory parts to bring the motor back into factory specs. I used Tohatsu parts. Kind regards, Aussie Boat Guy 😎

[@toupsclassroomtoupsclassro9557]

Question: let's say a 70 hp yam 2 stroke with one cylinder down 70psi and rest say 110 what would you suppose would need to be done? hone or bore?

[@25hpboatracerman]

Hi Mate, It has most likely scuffed a bore (fingers crossed honing will sort but you won’t know till the head is removed) the piston will most likely need to be replaced as it will have scuffed sides and a new set of rings. Could need a bore but take the head off and check. Fibd out what caused the issue before rebuilding too do it doesn’t happen again, overheating? oil injection problem? should you remove the oil pump and run pre-mix? Cheers 🍻 Aussie Boat Guy 😎

[@toupsclassroomtoupsclassro9557]

@@25hpboatracerman can i use a sewer cam to see the inside of the cylinder? love your vid ty and thanks for your reply would love to try and rebuild one

[@25hpboatracerman]

Hi Mate, Sometimes, it is pretty hard to see what’s going on on the screen though. If the compression is 70 in one cylinder there is clearly a problem unfortunately. It’s up to you though, if it’s running ok then you could consider just using it. Cheers 🍻 Aussie Boat Guy 😎

[@Eugene-n1p]

hi how do you clean the power head before painting without getting water inside?

[@25hpboatracerman]

Hi Mate, Before I reassemble a powerhead I degrease it blow it down with compressed air and allow to dry. After reassembly just before paint I wipe the powerhead down with wax a as no grease remover then paint. cheers 🍻 Aussie Boat Guy 😎

[@pietlopsa9164]

What paint did you use? Looks very factory new!

[@25hpboatracerman]

Hi mate, I’ve actually tried a lot of different paints over the years but that is - believe it or not just a cheap quick dry paint - the brand is - White Knights Squirts. Cheers 🍻 Aussie Boat Guy 😎

[@williamhelmer9419]

Could you do a video on exhaust idle relief ports and ow they can affect water pump

[@25hpboatracerman]

Hi Mate, Not too sure what you’re asking? Cheers 🍻 Aussie Boat Guy 😎

[@williamhelmer9419]

I replaced my water pump, works with drill but won't pump water when I assemble it, only smoke or steam along with exhaust pulses come out the pee hole

[@williamhelmer9419]

Or show the route the water takes thought the engine, I'm sure the pump is pumping water but idk where its going There's not any blockages, I blew through it both directions with air

[@carwrapkingvinylwraps4097]

Yeah 😅

[@25hpboatracerman]

Lots of fun work 👍 Cheers 🍻 Aussie Boat Guy 😎

[@siulajonah4438]

I have a Mercury 15hp of 2015 and I need help in rebuilding it can you help me out

[@25hpboatracerman]

Hi Mate, You can follow along with some of my rebuild videos, the motors are all very similar. Cheers 🍻 Aussie Boat Guy 😎

[@aaronellinger2662]

Great job! Very coherent instructions. Thank you.

[@25hpboatracerman]

Hi Champion, No problem, glad you enjoyed it and really appreciate your support. Cheers 🍻 Aussie Boat Guy 😎

[@michaelsimpson9779]

Nice work. A thickish sheet of plate glass makes a nice lapping surface. Running the object on the emery paper in a figure of 8 pattern if youve got the room to do so is also a good idea. What do you think about filling a cylinder with starter cord or similar (keeping it out of the ports) to use as a stop to torque the flywheel down?

[@25hpboatracerman]

Hi mate, Thanks for your comments 😊 Totally agree your suggestions too. Cheers 🍻 Aussie Boat Guy 😎

[@JJP301]

I used that air craft sealer 40 years ago when I was a teen good stuff but didn't stay flexible like silicone but never had a leak.

[@25hpboatracerman]

Hi Mate, Yeah it’s good, the stuff I am using stays slightly flexible, well I’ve had a motor for about 15 years, that’s as long as I’ve tested it personally. The reason I don’t like the silicone gaskets is it can react with the alloy. cheers 🍻 Aussie Boat Guy 😎

[@portbogie2865]

Nice job brother!

[@25hpboatracerman]

Thank you! Cheers! Hope it helps Aussie Boat Guy 😎

[@mitchelldranow5069]

I am not presently intending on rebuilding an outboard, but I watched this video to see what I could learn about the design and structure of a small outboard. The video was great. Everything was well explained and the clarity of your filming was outstanding. Keep up the good work, mate!

[@25hpboatracerman]

That’s awesome 👏 Thanks for your comments mate, it was a long process to get that video finished and glad it helped. All the best, Aussie Boat Guy 😎

[@SaltyQuokka]

Awesome. Looks like more work went into the edit than the rebuild🤙🏼

[@25hpboatracerman]

😂😂 yep and if definitely made the rebuild long. I did want to get a rebuild video out though as I am hoping it helps sone people with the confidence to try it. Cheers 🍻 Aussie Boat Guy 😎

[@Diesr]

Ballbearings how interesting 😅 I thought I’d be rollers cause of the force of combustion pushing it sideways (does it have crankshaft play at all?)

[@25hpboatracerman]

Hi mate, Yep, ball bearings. No play at all. All of the outboards I build have ball bearings on the crank. It does have roller bearings on the big and small ends. Can’t remember building a motor that didn’t have ball bearings on the crank?? What motors are you building that don’t have ball bearings on the crank? I’m very interested, possibly older OMC Johnson - Evinrude or something. I have not built older than 80s merc either. Cheers 🍻 Aussie Boat Guy 😎

[@Diesr]

@@25hpboatracerman ive been gaining experience from open heart surgery on my 1979 jhonson/evinrude 15hp seahorse its a beast but sadly one ring might be gone on top so no compression but i suggest it anyways cause it runs and theres rumors where it runs on a broken crankshaft and not being noticed (sorry for lack of punctuation my keyboard broke)

[@josephhalwagy6435]

thanks for sharing. Working on a two stroke ICE is a lot of fun.

[@25hpboatracerman]

Hi mate, Thanks 👌 Yeah, I love tinkering with the two strokes 😁 Cheers 🍻 Aussie Boat Guy 😎

[@belavita]

How mucht the torque for head screw?

[@25hpboatracerman]

Hi 👋 Each motor has a different torque setting for specific bolts, you will have to check with your manufacturer. cheers 🍻 Aussie Boat Guy 😎

[@willknight1005]

Paint job 👌

[@25hpboatracerman]

Cheers mate 🍻 I had to make it pretty All the best, Aussie Boat Guy 😎

[@andyd6033]

Looks good legend!

[@25hpboatracerman]

Thanks champion 👌 All the best, Aussie Boat Guy 😎

[@RedHighlands]

Great Video, Great Teacher.

[@25hpboatracerman]

Hi Mate, Thanks for your encouragement, I really appreciate you taking the time to comment champion. Cheers 🍻 Aussie Boat Guy 😎

[@MrAnthonyfrench]

sounds sweet !!

[@25hpboatracerman]

Cheers 👍 Yeah, they are good motors. All the best, Aussie Boat Guy 😎

[@rickycox6486]

@25hpboatracerman I just rebuilt my 20hp 4 stroke Tohatsu and I had take 0.2032 mm off the head because it was warped. Now my timing belt is loose/ too long. Do you have any suggestions on what to do?

[@25hpboatracerman]

Hi mate, Yeah, that’s a hard one. I am not too sure about the 20 four stroke when the head is shaved. New head probably unless sone sort of tensioner can be adjusted. Sorry I’m not more helpful on this one. Cheers 🍻 Aussie Boat Guy 😎

[@NicolasTorreonJr]

Nice vid. Mate

[@25hpboatracerman]

Thanks Champion 👍 Aussie Boat Guy 😎

[@qldshane]

Good work on the vid, looking forward to the boat tests! I’m currently working on my trailer and 8ft punt getting it ready for its 9.8hp Tohatsu 2 stroke. We can compare top speeds! 👍

[@25hpboatracerman]

Thanks mate 👌 Yeah, will actually be a good comparison, your 8ft punt should fly 😁. All the best, Aussie Boat Guy 😎

[@honeybadgeractual5734]

Question, I am considering converting an old Johnson sea horse to a liquid cooled go kart for playing with, do you have any experience with appropriate cooling setups for one of these little motors to operate out of an aquatic environment

[@25hpboatracerman]

Sounds like an awesome project. I do know that outboards run pretty cool as they have full access to cold cooling water. I reckon if you had a big radiator, thermo fan and water pump you should be fine. There are a few people who have used outboards power-heads out of the water. You can search on KZbin outboard motorbike and that should bring something up, you may be able to ask him if he had any issues cooling. Cheers 🍻 Aussie Boat Guy 😎

[@jimstaines8093]

Awesome! I'd be pretty keen to have this done to my 2001 Merc 9.9/15

[@25hpboatracerman]

Hi mate, yeah it’s really fun, so much work and time though. I have not modified the USA built 9.9 - 15hp. cheers 🍻 Aussie Boat Guy 😎

[@MrSilva777]

Awesome video man, will definitely be helpful for my 15hp Merc when I need to do some work on it!

[@25hpboatracerman]

Thanks mate, yep, pretty much the same deal with the 15 Mercury. Was a mission of a video to make and edit, I know it won’t get many views but I’m hoping it helps people when they need a video to follow along with as they rebuild an outboard. Cheers 🍻 Aussie Boat Guy 😎

[@bradleyfarquhar2023]

good job mate that will help me when its time for a rebuild on my outboard. Nothing better then a rebuild will go a lot smother and run really well cheers mate u are the man when it comes to outboards boating and others cool things.

[@25hpboatracerman]

Thanks so much mate for your encouragement, that was a mission filming and editing that vid. Hope it helps people. Cheers 🍻 Aussie Boat Guy 😎

[@keithmanion1282]

Excellent video with clear explanations, attention to detail and great editing. Thanks.

[@25hpboatracerman]

Thanks so much mate, I found editing that one a long process and my camera isn’t the best so I really appreciate your encouragement champion. All the best, Aussie Boat Guy 😎

[@ronthegunman5724]

Nice video. Bedst regards from Denmark 🇩🇰

[@25hpboatracerman]

Thanks mate 👌 I appreciate your encouragement. All the best from Australia 🇦🇺 Cheers 🍻 Aussie Boat Guy 😎

[@craigfriend3748]

Great job buddy

[@25hpboatracerman]

Cheers 🍻 That’s the motor we used the other day 😂

[@gandrewboyd]

Great video! What year/model Tohatsu is this?

[@25hpboatracerman]

Hi mate, Thanks, I appreciate your comments 😊 Think it’s a 2006 model. Pretty sure they are the same from 2003 on. Cheers 🍻 Aussie Boat Guy 😎

[@gandrewboyd]

I have an ancient Nissan/Tohatsu NS18C (late 1980s?) and it’s hard to find many parts. At around what year do you find the parts become easy to get? Thanks!

[@25hpboatracerman]

@@gandrewboyd Hi mate, You got a good motor there. I think you should still be able to get parts for your motor, I think parts get easier to get from a 1996 model 18c2. Cheers 🍻 Aussie Boat Guy 😎

[@Madmick82]

Hey mate, What paint did you use on the powerhead?

[@25hpboatracerman]

Hi mate, Nice hey 👌 Tried a lot of paints over the years but that paint is surprisingly just a cheap quick dry can spray called White Knights Squirts gloss black. It’s only a acrylic paint but it really has great coverage and the finish is nice it doesn’t react to a small amount of contamination on the surface although you should still use wax and grease remover. Cheers 🍻 Aussie Boat Guy 😎

[@Madmick82]

@@25hpboatracerman Cheers, It looked like it gave it a really solid coating.

[@25hpboatracerman]

@@Madmick82 Yeah, I’m impressed with that paint. Good for power heads on outboards, good for gearcase touch up. Cheers 🍻 Aussie Boat Guy 😎