I just bought a 15 h.p Tohatsu and 18 Nissan, both 2 strokes. The 18 Nissan runs great on the stand on the muffs but not on the boat in the water, it lacks power, the compression is supposedly good in both cylinder's and lower unit is good with no signs of wear, no slop or funny sounds. I'm hoping for clogged fuel filters or something simple. It looks like the motors zip along pretty good. I have a bullet proof 8 h.p Tohatsu also. Sweet motors. I think they ar all made buy Tohatsu? Under 30 h.p Mercury, Nissan and Yamaha I'm almost certain.
Are you sure the 18hp is running on both cylinders. I would want to personally see the compression, people always say compression is good, not always true. Pull the plugs and connect leads, rest them against the block and pull the cord to check for spark. If you run the motor on a stand pull the spark plug leads off and put them on one at a time (with insulated pliers) while running and see if the motor note changes. Check compression with a gauge. If you have good comp (over 110 for the 18hp, more like 140psi) and spark then It should be carburetor issue. Hope you can diagnose it. Cheers
Hello, my trimaran is powered by 9.8 4 stroke Tohatsu with the 25" shaft. Heavy bugger. I like it but... It's making oil and smoking more than it did. It fairly new to me both boat Farrier 31 and the Tohatsu. I replaced the fuel pump right away when I got it and serviced it bc I smelled gas in the fuel. I changed the oil and thought it was fixed, but it's back. Making oil.
Hi mate, That’s annoying for you. I’m not too familiar with the 4 stroke outboards only the two strokes. I’m not too sure why your motor would be smoking. Is it only when it’s cold? Or all the time?
@@bizeigelI'm assuming this is blue smoke, I.e. semi-burnt oil? 4 stroke engines usually burn oil either because their oil control rings are bad/clogged (oil gets past rings into combustion chamber) or because they have excessive blowby (bad cylinder liner or compression rings) and the oil is being blown away through the PCV system. If it's making oil that means that petrol is getting past the rings into the crankcase, which is more suggestive of a compression issue. You also need to check the thermostat, 'making oil' is often caused by fuel condensing on the inside of the cylinders when the engine is cold. If the engine gets a decent run at normal operating temperature during use any fuel mixed with the oil should evaporate out and get sent into the cylinders to be burned via the PCV. If your thermostat is stuck open the engine may never heat up, leading to this issue. The condensed fuel also dilutes the oil on the cylinder liners and causes them and the rings to wear out faster. If on the other hand you are seeing black smoke, that means the carb is set way too rich. This could also lead to increased dilution of the engine oil with fuel, along with really bad performance.
Great info thanks, just bought a 15 Super and am going to change the cam to a Tohatsu one. Do you know if the props are the same on both 18hp Tohatsu and Merc 15 Super? Or does the prop need changing too to avoid over-revving? Cheers!
Hi Mate, Great motors 👌 you may be able to advance the timing a tad too to get a bit more power too. the props are the same, the long shaft 15 super and 18 tohatsu both came stock with a 9p and the short versions both came with a 10p. You should be able to hear if it’s over revving. Also changing the cam on the 15 super really doesn’t add much unfortunately. Cheers 🍻 Aussie Boat Guy 😎
I have a mercury 2 stroke 9.9 hp, and on the cylinderhead is a stamp of nr. 55. Do you mean by changing the carb only the outboard engine will become a 15 hp?
Hi, i have checked the parts manual online, and see that the carb for 9.9 and 15 hp are the same. They have different powerhead partnumbers. I gues what should be the difference of the powerhead?. Please can you check in the manual you displayed in the video for the mercury, how many cc is the 9.9 and the 15 HP? The model nr. of my mercury 9.9 is 1010203EL. Serial no. is 0N377091
Any chance you could do a step by step on changing the cam off the stator to hot up a super 15 to 18? I’d love to do it to mine and there doesn’t seem to be anything on TH-cam
Hi mate, Unfortunately I don’t have the motor at the moment to do that too. Noticed the other day too that some 15 supers came with a 20mm throat in the carburetor but the 18hp has a 22mm throat. You could check that too. Also I kind of already have a video on removing the stator on that motor so you could watch that as that’s all the video would be apart from swapping the cam, it’s the 15 - 18hp tear down video. Cheers 🍻 Aussie Boat Guy 😎
Side by side, do the 9.9 & 18 blocks look the similar from the outside? Might a park ranger believe an 18 were actually a 9.9 if I changed the stickers
Hey mate, They look exactly the same from the outside. Unfortunately they do have a stamp on the starboard side top of the block (near the head) that will give it away. The 9.9hp and 15hp have a 55 and the 18 have a 60 stamp, that is to show the bore size in millimeters. In saying that, if you have a 9.9hp you could make it a 15hp with the 15hp carburetor (also the 15 carb has a different part number but is a pretty small print) The 55 and 60 stamps are very noticeable. Cheers
I understand they will have different 55 and 60 stamp which are noticeable with the cowl off. However. Are the exhaust tuner the same between 9.9 mercury and 18hp Tohatsu? Could I pull my Tohatsu powerheads off at the leg, including carb and ignition coil etc, And buy a 9.9 do the same to that, then, Bolt the 18 powerhead on the 9.9hp stamped leg. Then use a 9.9cowl So essentially It looks like a 9.9 from the outside, but rip the cowl up, and real will know, but the UNeducated will remain?
You should have mentioned converting the 9.9 (not the 9.8) by changing to the 15 throttle cam. Just like the Super 15 Merc, the carb doesn't fully open on the 9.9.
Good question 👌 Unfortunately not that simple. If you upsize the main jet (which is matched perfectly to the carburetor throat size) you will just loose speed because it will be running too rich, if you go smaller it will run lean. Slightly leaner sometimes runs faster but blows motors really quick do not a good idea. If you make the throat of the carburetor bigger then you can go bigger with the main (high speed) jet. That’s a fair amount of effort and you may not see too much gain without other mods like further porting, exhaust work etc. Shaving the head (adding compression) does definitely give the 18 more torque but I have not noticed a gain top end. If it’s just grunt or torque your after then try a lesser pitch prop. I have a 10p on my current 18hp but if I load the boat I put a 9p on. Cheers mate 👍
Hi, really nice video. I have replaced throttle cam, and adjust the ignition timing I don't know whether Mercury 15hp carb is same with Tohatsu 18hp carburetor? Do you know any information? Thank you~
Good thought, I’m not sure though, I would have to check wether the smaller head fowls on the pistons. Also how much cc each head has in itself (wether it would increase comp) It is probably easier to shave the standard larger capacity head, I have done this and it worked well. It did not increase top end speed but it did add more torque and a noticeable increase in acceleration from stop.
Ya I wasn’t sure if they bolted up but was just a thought, I own many Johnson 9.9/15 and have been wanting to build one with better pistons and reeds but haven’t really found any pistons
The 9.9 and 15hp Johnson - Evinrude are fun to play with, I put two 15hp carburetors on one and shaved the head plus put low water pick ups and a tricked up prop. Wish I could upload a pic to this page. That motor used more fuel than a 50hp Johnson, worth it! Cheers, Glenno
Hey mate 👋 The blocks in the video are 2003 and newer. A 95 model 18hp Nissan - Tohatsu is still a great motor and a fair few parts are interchangeable. I believe the bottom seal on your crank is different and the block is a bit different, plus a few other things. Cheers
I have a 15hp mercury Japanese made. I'm told it is actually an 18hp tohatsu. How can i tell for sure? And if it really is a 15hp, is the 18hp tohatsu much more grunty? I need more power and thinking of buying 18hp T.
Hi mate, You can tell it’s an 18hp block by it having 60 stamped on the block near the head, a 9.9hp and 15hp have 55 stamped. Also your carburetor doesn’t open fully and your timing is a bit retarded compared to the 18hp. It honestly would be hard to tell much of a difference if you upgraded it to 18hp mate. Just get the 25 - 30hp two stroke if you need a heap more power. Cheers 🍻 Aussie Boat Guy 😎
@25hpboatracerman BTW FWIW we reluctantly sailed away from Australia last year after spending 3 years (nearly) circumnavigating your amazing country. Incredible memories and friends made. Rob
Hi mate, Unfortunately I only do it for my myself. It’s not too hard, just order the 18hp cam, remove your flywheel and stator, change the cam and re-assemble. Not a massive difference in performance, but it’s there. Cheers
Hey I've been trying so hard I want to bring my tohatsu 8 hp outboard back to restore my engine block powerhead has a lot of corrosion this engine was given to me as a gift I'm trying to restore it back it's a tohatsu M8B 8hp I was wondering maybe you would know what other brand or power head from another brand with it into the tohatsu lower bracket
@@giolovelife3876 Hi mate, I use the Japan built Mercury parts for tohatsu all the time. You just need to make sure the Mercury says made in Japan on the label - near the serial numbers. The Japan built Mercury is built by Tohatsu and the 6,8,15,40hp two stroke are the same as tohatsu, make sure visually it is the same too but I’ve used a lot of that to fix my tohatsu outboards through the years also used tohatsu to fix my Japan built Mercury. Cheers Aussie Boat Guy 😎
It is easy, it’s actually just a different shaped cam! You can buy one for the 18hp Tohatsu and it bolts on. From memory I think I have always taken the stator off the power head to change them but it possibly can be done while the stator is on the motor. Either way be prepared to remove the stator. Cheers
You can, but unfortunately the 9.8hp tohatsu is basically a worked 6hp (So already all the best bolt on bits are on the 9.8hp). It has higher compression, bigger carbie etc. I feel it’s already getting good horsepower for its 25kg and 169cc capacity. If you are really after more power from it I would start with more compression, porting (be very careful as you can lose power very easily), carburetor and exhaust tuner. even after all those mods I don’t think you would see much more than 12hp. If it’s speed you are chasing I would go a lighter boat and play with props (surface piercing). Hope this helps Cheers,
Hey mate, the 9.9hp can’t be converted to the 18hp as it’s a smaller bore motor about 50cc less. It can be converted to the 15hp though, I think it’s just the carburetor. Cheers mate
mate, quick question, do you think its worth it to buy tohatsu 18 than any 15hp yamaha/suzuki/merc in terms of power. coz tohatsu 18 is more expansive about 130 usd from those 15 engine in my country.
The 15hp Mercury super (Japan built) is actually an 18hp tohatsu. The Suzuki 15 and the Yamaha 15 are both great motors. The 15hp Mercury USA built is a good motor as well. Are you talking about all two strokes? Cheers
Hi Champion, Yes the 18hp Tohatsu and the 15hp Mercury Super are the same motors. The only difference is the throttle cam that opens the carburetor - the 18hp cam is larger opening the carburetor butterfly all the way. Also the timing is afvanced on the 18hp. They use the exact same carburator, its just that the 15hp super does not open all the way because of the throttle cam on the stator. Its an easy upgrade. Cheers, Aussie Boat Guy 😎
Muito o brigado pela informação, sor mais ua pergunta meu Mercury super eu au mentei a se relação do au final do game tudo o moto vibra e faz um rotação tipo pedindo combustível será que eu tenho msmo que fazer o procedimento de passa bloca no giclé do carburador
Sorry mate, hope you can find what your looking for. Also you can tell they are all two stroke, 4 stroke has the ports in the head not the block. Are you hoping to get more hp out of your 4 stroke? Cheers
Hey mate you should do a detailed video on cleaning the carb on the 18hp tohatsu. Cheers for the vid
Next time I do a carbie on an 18hp tohatsu I will put it on TH-cam. May be a while though, I have a pile of other hp motors to get through first.
I just bought a 15 h.p Tohatsu and 18 Nissan, both 2 strokes. The 18 Nissan runs great on the stand on the muffs but not on the boat in the water, it lacks power, the compression is supposedly good in both cylinder's and lower unit is good with no signs of wear, no slop or funny sounds. I'm hoping for clogged fuel filters or something simple. It looks like the motors zip along pretty good. I have a bullet proof 8 h.p Tohatsu also. Sweet motors. I think they ar all made buy Tohatsu? Under 30 h.p Mercury, Nissan and Yamaha I'm almost certain.
Are you sure the 18hp is running on both cylinders. I would want to personally see the compression, people always say compression is good, not always true.
Pull the plugs and connect leads, rest them against the block and pull the cord to check for spark.
If you run the motor on a stand pull the spark plug leads off and put them on one at a time (with insulated pliers) while running and see if the motor note changes.
Check compression with a gauge.
If you have good comp (over 110 for the 18hp, more like 140psi) and spark then It should be carburetor issue.
Hope you can diagnose it.
Cheers
Hi there mate I just bought a 15 super mercury for a 3m polycraft tuffy. Great video. Pretty keen to see how she goes.
Hi mate,
Should go pretty well on the 3m poly! They are great little motors for sure.
Cheers 🍻
@@25hpboatracerman th-cam.com/video/PgDWw6UKjz0/w-d-xo.html
Tha ks for your help by the way.
Too easy mate
TOHATSU 18.. 👍👍
Would have if I could have. 15 super is what I got.
Hello, my trimaran is powered by 9.8 4 stroke Tohatsu with the 25" shaft. Heavy bugger. I like it but... It's making oil and smoking more than it did. It fairly new to me both boat Farrier 31 and the Tohatsu. I replaced the fuel pump right away when I got it and serviced it bc I smelled gas in the fuel. I changed the oil and thought it was fixed, but it's back. Making oil.
Hi mate,
That’s annoying for you. I’m not too familiar with the 4 stroke outboards only the two strokes.
I’m not too sure why your motor would be smoking. Is it only when it’s cold? Or all the time?
@@25hpboatracerman All the time. I need check compression. I'm thinking rings need renewed.
@@bizeigelI'm assuming this is blue smoke, I.e. semi-burnt oil? 4 stroke engines usually burn oil either because their oil control rings are bad/clogged (oil gets past rings into combustion chamber) or because they have excessive blowby (bad cylinder liner or compression rings) and the oil is being blown away through the PCV system. If it's making oil that means that petrol is getting past the rings into the crankcase, which is more suggestive of a compression issue.
You also need to check the thermostat, 'making oil' is often caused by fuel condensing on the inside of the cylinders when the engine is cold. If the engine gets a decent run at normal operating temperature during use any fuel mixed with the oil should evaporate out and get sent into the cylinders to be burned via the PCV. If your thermostat is stuck open the engine may never heat up, leading to this issue. The condensed fuel also dilutes the oil on the cylinder liners and causes them and the rings to wear out faster.
If on the other hand you are seeing black smoke, that means the carb is set way too rich. This could also lead to increased dilution of the engine oil with fuel, along with really bad performance.
Great info thanks, just bought a 15 Super and am going to change the cam to a Tohatsu one. Do you know if the props are the same on both 18hp Tohatsu and Merc 15 Super? Or does the prop need changing too to avoid over-revving? Cheers!
Hi Mate,
Great motors 👌 you may be able to advance the timing a tad too to get a bit more power too.
the props are the same, the long shaft 15 super and 18 tohatsu both came stock with a 9p and the short versions both came with a 10p.
You should be able to hear if it’s over revving.
Also changing the cam on the 15 super really doesn’t add much unfortunately.
Cheers 🍻
Aussie Boat Guy 😎
thanks for the information given mate.
I have a mercury 2 stroke 9.9 hp, and on the cylinderhead is a stamp of nr. 55. Do you mean by changing the carb only the outboard engine will become a 15 hp?
Hi Mate,
Pretty sure that’s the case along with advancing the timing.
Cheers 🍻
Aussie Boat Guy 👍
Hi, i have checked the parts manual online, and see that the carb for 9.9 and 15 hp are the same. They have different powerhead partnumbers. I gues what should be the difference of the powerhead?. Please can you check in the manual you displayed in the video for the mercury, how many cc is the 9.9 and the 15 HP?
The model nr. of my mercury 9.9 is 1010203EL. Serial no. is 0N377091
Any chance you could do a step by step on changing the cam off the stator to hot up a super 15 to 18? I’d love to do it to mine and there doesn’t seem to be anything on TH-cam
Hi mate,
Unfortunately I don’t have the motor at the moment to do that too.
Noticed the other day too that some 15 supers came with a 20mm throat in the carburetor but the 18hp has a 22mm throat.
You could check that too.
Also I kind of already have a video on removing the stator on that motor so you could watch that as that’s all the video would be apart from swapping the cam, it’s the 15 - 18hp tear down video.
Cheers 🍻
Aussie Boat Guy 😎
Side by side, do the 9.9 & 18 blocks look the similar from the outside? Might a park ranger believe an 18 were actually a 9.9 if I changed the stickers
Hey mate,
They look exactly the same from the outside. Unfortunately they do have a stamp on the starboard side top of the block (near the head) that will give it away.
The 9.9hp and 15hp have a 55 and the 18 have a 60 stamp, that is to show the bore size in millimeters.
In saying that, if you have a 9.9hp you could make it a 15hp with the 15hp carburetor (also the 15 carb has a different part number but is a pretty small print)
The 55 and 60 stamps are very noticeable.
Cheers
I understand they will have different 55 and 60 stamp which are noticeable with the cowl off. However.
Are the exhaust tuner the same between 9.9 mercury and 18hp Tohatsu?
Could I pull my Tohatsu powerheads off at the leg, including carb and ignition coil etc,
And buy a 9.9 do the same to that,
then, Bolt the 18 powerhead on the 9.9hp stamped leg. Then use a 9.9cowl
So essentially It looks like a 9.9 from the outside, but rip the cowl up, and real will know, but the UNeducated will remain?
Thank you champion 🍻
No Problem Champion.
Cheers 🍻
Aussie Boat Guy 😎
You should have mentioned converting the 9.9 (not the 9.8) by changing to the 15 throttle cam. Just like the Super 15 Merc, the carb doesn't fully open on the 9.9.
is there any way you can get a bit more grunt out of the 18M1e2 by jet up grade ect, ect????????
Good question 👌
Unfortunately not that simple.
If you upsize the main jet (which is matched perfectly to the carburetor throat size) you will just loose speed because it will be running too rich, if you go smaller it will run lean. Slightly leaner sometimes runs faster but blows motors really quick do not a good idea.
If you make the throat of the carburetor bigger then you can go bigger with the main (high speed) jet. That’s a fair amount of effort and you may not see too much gain without other mods like further porting, exhaust work etc.
Shaving the head (adding compression) does definitely give the 18 more torque but I have not noticed a gain top end.
If it’s just grunt or torque your after then try a lesser pitch prop. I have a 10p on my current 18hp but if I load the boat I put a 9p on.
Cheers mate 👍
Hello sir 15hp yamaha 2stroke n 4stroke which one good for long run sir??
Hi Mate,
i personally like the two stroke but for a long run the four stroke will use less fuel.
Cheers 🍻
Aussie Boat Guy 😎
Hi, really nice video. I have replaced throttle cam, and adjust the ignition timing
I don't know whether Mercury 15hp carb is same with Tohatsu 18hp carburetor?
Do you know any information? Thank you~
Hi mate,
Thanks,
Yep, same carburetor on the Mercury 15 super as the 18hp Tohatsu.
Cheers 🍻
Aussie Boat Guy ❤️
@@25hpboatracerman Thank you, mate! 🥂
Thanks a lot 4 the information.
Hey man one question. Do you know if rhe tohatsu 9.9/15hp has an anode right behind the exhaust plate?
Hi mate,
In some I have disassembled there has been an anode behind the exhaust plate.
cheers 🍻
Aussie Boat Guy 😎
Could you put the smaller cc head on the larger bore engine to up the compression ratio thus add more horsepower?
Good thought, I’m not sure though, I would have to check wether the smaller head fowls on the pistons. Also how much cc each head has in itself (wether it would increase comp)
It is probably easier to shave the standard larger capacity head, I have done this and it worked well.
It did not increase top end speed but it did add more torque and a noticeable increase in acceleration from stop.
Ya I wasn’t sure if they bolted up but was just a thought, I own many Johnson 9.9/15 and have been wanting to build one with better pistons and reeds but haven’t really found any pistons
The 9.9 and 15hp Johnson - Evinrude are fun to play with, I put two 15hp carburetors on one and shaved the head plus put low water pick ups and a tricked up prop.
Wish I could upload a pic to this page.
That motor used more fuel than a 50hp Johnson, worth it!
Cheers,
Glenno
Great video!! Very well done! Would you know the difference from the 9.9 to the 12 or 15hp?
I have a 9.9 and would like to modify it thanks!
2 stroke or 4 stroke? if its 2 stroke an expasion chamber mod could almost get 30 hp
What year are the blocks? I just bought an 18 Nissan '95...thanks for any insight. Cheers.
Hey mate 👋
The blocks in the video are 2003 and newer.
A 95 model 18hp Nissan - Tohatsu is still a great motor and a fair few parts are interchangeable.
I believe the bottom seal on your crank is different and the block is a bit different, plus a few other things.
Cheers
Hi mate ! What about the electrics... ignition coil and CDI, are those the same ?
Hi mate,
Exactly the same electrics.
Cheers
I have a 15hp mercury Japanese made. I'm told it is actually an 18hp tohatsu. How can i tell for sure? And if it really is a 15hp, is the 18hp tohatsu much more grunty? I need more power and thinking of buying 18hp T.
Hi mate,
You can tell it’s an 18hp block by it having 60 stamped on the block near the head, a 9.9hp and 15hp have 55 stamped.
Also your carburetor doesn’t open fully and your timing is a bit retarded compared to the 18hp.
It honestly would be hard to tell much of a difference if you upgraded it to 18hp mate.
Just get the 25 - 30hp two stroke if you need a heap more power.
Cheers 🍻
Aussie Boat Guy 😎
@25hpboatracerman thanks for the quick reply. Yeah might look at the 25hp, same weight as the 30hp but a bit cheaper. Can still get new in se Asia.
Also the 25hp Tohatsu can be made into the 30hp by opening up the carburetor gasket and advancing the timing a bit.
Cheers 🍻
Aussie Boat Guy 😎
@@25hpboatracerman you're speaking in Russian now!😄
@25hpboatracerman BTW FWIW we reluctantly sailed away from Australia last year after spending 3 years (nearly) circumnavigating your amazing country. Incredible memories and friends made. Rob
What do they typically charge to change the cam on the 15 super to a 18 tohatsu
Hi mate,
Unfortunately I only do it for my myself. It’s not too hard, just order the 18hp cam, remove your flywheel and stator, change the cam and re-assemble.
Not a massive difference in performance, but it’s there.
Cheers
@@25hpboatracerman thanks for the quick reply. Ill look into it. 3m Tuffys are heavy little vessels.
The throttle cam ?
Hey I've been trying so hard I want to bring my tohatsu 8 hp outboard back to restore my engine block powerhead has a lot of corrosion this engine was given to me as a gift I'm trying to restore it back it's a tohatsu M8B 8hp I was wondering maybe you would know what other brand or power head from another brand with it into the tohatsu lower bracket
Hi mate,
The Japan built Mercury 8hp is the same motor so you should be able to use parts of a Japan built Mercury 8hp.
Cheers
Aussie Boat Guy 😎
Thank you for your help but what about the bracket where you going to bolted into the lower unit bracket is it the same holes where you screw them on
@@giolovelife3876
Hi mate,
I use the Japan built Mercury parts for tohatsu all the time. You just need to make sure the Mercury says made in Japan on the label - near the serial numbers.
The Japan built Mercury is built by Tohatsu and the 6,8,15,40hp two stroke are the same as tohatsu, make sure visually it is the same too but I’ve used a lot of that to fix my tohatsu outboards through the years also used tohatsu to fix my Japan built Mercury.
Cheers
Aussie Boat Guy 😎
hey mate may i knew.. its mercury 30hp its fit for 30hp yamaha? thanks mate
Thank you information
Hey mate, I don't really understand your comment.
But mercury 30hp is totally different than a 30hp Yamaha.
Cheers
Is it easy to swap the cam on the stater to get WOT on the super 15
Cheers
It is easy, it’s actually just a different shaped cam! You can buy one for the 18hp Tohatsu and it bolts on.
From memory I think I have always taken the stator off the power head to change them but it possibly can be done while the stator is on the motor.
Either way be prepared to remove the stator.
Cheers
25hpboatracerman what area are you in? Sydney?
Thanks for the reply 👍
Central coast NSW
@@25hpboatracerman i would think also adding a degree or 2 of timing would be needed as well?
Hey mate, any way of increasing the 9.8 tohatsu power wise? Cheers bud!
You can, but unfortunately the 9.8hp tohatsu is basically a worked 6hp (So already all the best bolt on bits are on the 9.8hp). It has higher compression, bigger carbie etc. I feel it’s already getting good horsepower for its 25kg and 169cc capacity. If you are really after more power from it I would start with more compression, porting (be very careful as you can lose power very easily), carburetor and exhaust tuner. even after all those mods I don’t think you would see much more than 12hp.
If it’s speed you are chasing I would go a lighter boat and play with props (surface piercing).
Hope this helps
Cheers,
The Aussie boat guy. Thank you for getting back much appreciated subscribed!
Do u know how to convert the 9.9 tohatsu to 18 hp?
Hey mate, the 9.9hp can’t be converted to the 18hp as it’s a smaller bore motor about 50cc less. It can be converted to the 15hp though, I think it’s just the carburetor.
Cheers mate
@@25hpboatracerman Ohh, okay. Thanks for the quick answear:)
mate, quick question, do you think its worth it to buy tohatsu 18 than any 15hp yamaha/suzuki/merc in terms of power. coz tohatsu 18 is more expansive about 130 usd from those 15 engine in my country.
The 15hp Mercury super (Japan built) is actually an 18hp tohatsu.
The Suzuki 15 and the Yamaha 15 are both great motors. The 15hp Mercury USA built is a good motor as well.
Are you talking about all two strokes?
Cheers
@@25hpboatracerman yea two stroke only. as i cant get 4 stroke easily here, plus the weight is so heavy.
Ok, well they are all pretty good.
I would personally go with the Japan built 15hp Mercury super as that is the 18hp tohatsu anyway.
@@25hpboatracerman thanks for the recomendation
No intende muito pq falo português mais mim explica o msmo moto tohatso 18 é msmo moto Mercury super 15 sor muda carburador
Hi Champion,
Yes the 18hp Tohatsu and the 15hp Mercury Super are the same motors. The only difference is the throttle cam that opens the carburetor - the 18hp cam is larger opening the carburetor butterfly all the way. Also the timing is afvanced on the 18hp. They use the exact same carburator, its just that the 15hp super does not open all the way because of the throttle cam on the stator. Its an easy upgrade.
Cheers,
Aussie Boat Guy 😎
Muito o brigado pela informação, sor mais ua pergunta meu Mercury super eu au mentei a se relação do au final do game tudo o moto vibra e faz um rotação tipo pedindo combustível será que eu tenho msmo que fazer o procedimento de passa bloca no giclé do carburador
Fuuuuck...... You forgot to SAY at the begining that you were talking about TWO STROKE MOTOR !!!
Sorry mate, hope you can find what your looking for.
Also you can tell they are all two stroke, 4 stroke has the ports in the head not the block.
Are you hoping to get more hp out of your 4 stroke?
Cheers