Outboard head gasket replacement

Thought I would put this video up as it may help people who are trying to replace a head gasket or head on their outboards.
Be patient with removing old bolts as it is better to spend a few minutes removing the bolt than snapping it and having to drill it out and do a thread repair.
Hope this video helps 👍
Cheers

[@seriksson9721]

How lucky I am, as I have the same error on my tohatsu 9.9 from 2000. Always good videos from you. Thanks from Sweden.

[@25hpboatracerman]

Hi Champion 👋 Thats so awesome and the reason I put up this video, your comments are really appreciated. thanks so much and cheers 🍻 Aussie Boat Guy 😎

[@joehozzy2616]

Very good instructional video. Thank you for sharing.

[@25hpboatracerman]

Hi Champion, My pleasure and thanks for your encouragement. cheers 🍻 Aussie Boat Guy 😎

[@ardynottle]

Again, another great video. Have a great Christmas 👍👍

[@25hpboatracerman]

Hi Mate, Thanks so much for your encouragement and I hope you have a great Christmas as well. Cheers 🍻 Aussie Boat Guy 😎

[@tutsijy]

Хорошее видео. Молодец! Всё понятно и грамотно сделано.

[@25hpboatracerman]

Привет Чемпион! Спасибо за вашу поддержку. Приветствую 🍻 Австралийский лодочник 😎 Privet Chempion! Spasibo za vashu podderzhku. Privetstvuyu 🍻 Avstraliyskiy lodochnik 😎

[@random_dude_99]

Those bolts are a pain to get off after years. When i took mine off i snapped the last bolt and it took me days to remove it since an extractor couldn't work🤦

[@25hpboatracerman]

Hi champion Yeah, sometimes they snap even with all the tricks and patience. I have snapped 5 on another 15 super before, was a painful time 🤦‍♂️. in saying that I repaired the threads and that motor is the one I use a lot for the last few years. Well done on repairing your one 👍 cheers 🍻 Aussie Boat Guy 😎

[@SaltyQuokka]

Great vid. Thanks for the tips and tricks🤙🏽

[@25hpboatracerman]

Hi Mate, No problem 👍 all the best and cheers 🍻 Aussie Boat Guy 😎

[@josephhalwagy6435]

Thank you for sharing

[@25hpboatracerman]

Hi Mate, Too easy, thanks for your comments 👍 cheers 🍻 Aussie Boat Guy 😎

[@DaveGregory3298akaDJ]

Very interesting bro

[@25hpboatracerman]

Hi Champion, thanks for your comments cheers 🍻 Aussie Boat Guy 😎

[@seriksson9721]

7.30 some oil or grease perhaps? Maybe also on the bolts when the gasket is to be mounted, to prevent it rusting together so easily?

[@25hpboatracerman]

Hi Mate, thanks for your input and good question 👍 I don’t really like to use oil or grease when I’m cleaning the threads as I blow them out with compressed air after and it’s normally just chalky residue. I do agreed that a slight amount of grease on the bolts, including thread and shafts, does help on disassembly down the track but you need to be very careful not to add too much as it can squeeze out and interfere with the head gasket impregnated sealer. cheers 🍻 Aussie Boat Guy 😎

[@seriksson9721]

You yourself noticed how difficult it was to loosen rusty or oxidized bolts. It is a problem in fresh water and an even bigger problem in salt water. Thanks again for the response and your nice videos.

[@jorgematos4895]

Grease absorbs water, oil will be washed up. I use ligth thread lock with good results.

[@jorgematos4895]

Yamaha shop manual say: Use LOCKTITE!

[@25hpboatracerman]

Yep, they get stuck for sure. I do like to apply a small amount of grease to the threads but I don’t advertise that too much as like I said if you apply too much it squeezes out the threads and affects the head seal. Thanks for your comments champion. Cheers 🍻 Aussie Boat Guy 😎

[@Rlip]

Be prepared to drill and tap those old bolts. Don’t replace unless you need to !

[@25hpboatracerman]

Hi mate, Absolutely and could not say it better myself 👍👍 only if you need to cheers 🍻 Aussie Boat Guy 😎

[@user-uq9dz4fp8v]

Hi, friend. I don't understand English, so I only look at pictures. But a lot of this is clear, but not everything. I have an old Tohatsu 6 2t engine. I want to convert it to 9.8. The carburetor will need to be replaced. And what else? Please list everything, and then I will translate it using Google. Thank you.

[@25hpboatracerman]

Hi Mate, I did put up a video on my channel that shows the difference between the 6 8 and 9.8hp that should answer your questions. The carburetor, the head, the exhaust cover and the stator stop Cheers 🍻 Aussie Boat Guy 😎

[@bunndyboy]

Hey mate, are the bolts on Japanese motors metric ? Keep them vids coming mate...

[@25hpboatracerman]

Hi Champion, Yes they are metric. Cheers 🍻 Aussie Boat Guy 😎

[@bradleyfarquhar2023]

Nice one mate on replacing a head gasket on this motor.I just brought a mercury 15 super the other day it’s a 2010 model and it’s only done around 2 hours on it after sitting in storage the new motor is awesome. One question do I have to retorque The head bolts some time when they new since it’s basically a new motor??

[@25hpboatracerman]

Hi mate, thanks for your encouragement 👍 To answer your question, I believe that you are supposed to re-torque the head bolts but no one does. I have re-torqued in the past on motors that I have rebuilt and still owned at the time a re-torque was required. Also owned a new (my only new motor 😂) 25hp Tohatsu built Mercury (for racing) and I did not re-torque as it would break the paint on the bolts and I would fail scrutinizing, raced that motor hard for seven years with no issues. cheers 🍻 Aussie Boat Guy 😎

[@bradleyfarquhar2023]

Ok mate cos it was a new outboard very hard to find a motor with around 2 hours of work.And I looked at it couldn’t pass it up had to buy it a little upgrade to my old mariner. Had a closer look at the pain on the head bolts it’s no missing should I just leave it or retorque the head bolts just a little worried mate?? cheers.

[@25hpboatracerman]

I would probably personally leave it as there is a risk of snapping bolts at this late stage, normally re-torque is around 12 months I believe. It’s up to you, it might be easy as it has been sitting not really used and the more I think of it, maybe I would do it but probably be fine either way. I would definitely do a water pump impeller as a minimum. Cheers 🍻 Aussie Boat Guy 😎

[@bradleyfarquhar2023]

Ok mate thanks again and have a great Christmas buddy cheers.

[@25hpboatracerman]

cheers mate, Hope you have a great Christmas season too 👍

[@brendonprice6550]

Hey mate I just recently got a tinny with a 25hp sea pro and it’s been sitting for about 8 years untouched. Any recommendations on what I should do before I try start it up? I don’t want to do any damage

[@25hpboatracerman]

Hi mate, Personally I would put some muffs on it, turn the water on (or put in a bucket) and try start it. It will probably need a carb overhaul, definitely needs an impeller but before spending any money I would get it running. Things to do would be an impeller, change the gear oil in the lower unit and probably a carburetor overhaul. Keep me posted Cheers 🍻 Aussie Boat Guy 😎

[@brendonprice6550]

Hey mate gave the carb an overhaul with the help of your video 👍… new plugs and fuel and got it running.. wasn’t pumping water so stopped it straight away … any recommendations on who to order a new impeller kit from online?

[@christopherbennett2078]

M8. Cheers for another good vid. I’ve got the 9,9 Tohatsu version of same with a bad tick/knock sound whilst compression still good. Thinking bearing issue. My issue is parts prices being out of this world in Norway as only supplier is Tohatsu and what I would typically need for repair in money terms would equate to a new 4 stroke. I want to stick with 2 stroke for the poke to weight ratio. In your neck of the woods: where would you go for a good used or reconditioned 18hp power head and carb that’s not an arm and a leg? Thinking upgrade vs repair would also be bang for the same buck. Appreciate any advice

[@25hpboatracerman]

Hi Champion, Oh mate, I feel your pain, I’ve got one sitting there with the same issue 🤦‍♂️. unfortunately when a big end bearing goes on that motor it is normally the whole crank assembly you need to source. I would definitely pull your motor down to see what is required (you can follow a tear down vid I did on the 15 super) Often trying to buy a whole motor with lower unit problems or snapped clamp bracket etc to rob the powerhead from is the most economical way. Hope you find a 18hp powerhead mate 👍 cheers 🍻 Aussie Boat Guy 😎

[@boatsandoutboards9070]

I never used a 2stroke . Is it really worth to spend that money on a 10+ years old 9.9hp engine for 12kg weight reduction? Is there any other reason? If you can upgrade it to 18hp, then do it of course

[@christopherbennett2078]

@@boatsandoutboards9070 Hi. In my opinion 4 strokes feel lazy and as you say weighs more. In the low hp range intended for small dingies this makes a big difference. If you take a 9,9hp 4 vs 2 stroke and test on the same boat the 2 stroke will beat the 4 stroke on acceleration, early planing and top end. The downside side is emissions and fuel consumption. My main rationale is the simplicity of the 2 stroke. As I operate in remote locations the ability to maintain and fault find with rudimentary tools weighs heavy in my consideration

[@boatsandoutboards9070]

@christopherbennett2078 Ok, I got your point, but I still stand for the 4stroke. Good luck with the repair

[@25hpboatracerman]

I agree totally with the small outboards - under 50hp. In my tests the two stroke out performance the 4 stroke equivalent as well. Above 50hp four stroke is a good option if you can afford it and don’t mind the extra weight (they are getting lighter though) Cheers 🍻 Aussie Boat Guy 😎

[@random_dude_99]

One question. Do you know if the 25-30hp tohatsu 2 stroke crankshaft is the same as the 9.9-15 hp crankshaft?

[@25hpboatracerman]

Hi Mate, The 9.9 - 15 - 18hp crank is totally different than the 25 - 30hp crank, it’s a fair bit smaller. Cheers 🍻 Aussie Boat Guy 😎

[@random_dude_99]

@@25hpboatracerman thanks

[@thegunnut221]

Shame not to see you use some sort of anti-seize applied to the reinstalled head bolts. Saves a lot of headache pulling the head again down the track.

[@25hpboatracerman]

Hi Mate, good point 👌 I did put a thin amount of grease on the threads but don’t like advertising it as if people use too much is squishes out and affects the head gasket sealer causing head leaks. it’s often best to re-install like the factory does anyway but like you pointed out bolt removal down the track gets really hard. Cheers 🍻 Aussie Boat Guy 😎

[@FR54321]

whats the welsh plug for?

[@25hpboatracerman]

Hi Champion, I believe the Welch plugs are to allow for the casting of the water passage on the head. After casting the tube needs to be sealed, hence the plug. cheers 🍻 Aussie Boat Guy 😎

[@FR54321]

@@25hpboatracerman ahhh makes sense, you should look into Thundercats and the motors for them. its right up your ally by squeezing as much hp out of a small motor. i reckon you could get a world record with one of those making them lighter and faster. you could get up to 150-170 with a 50 Tohatsu. have a think