im actually super keen for the mod video as i have 2 of these beut little motors. one will stay stock as im actually quite happy with it stock and i get about 27ks out of my little savage gull (11ft Tinny) on my own with a little bit of gear. on a 7.8 x 8 prop. the other is in bits but i just picked up the last bit to put it all together (needed a gearbox) also have a new 7.8 x 9 prop for it and im really wanting to get every last drop out of it just for kicks. i love playing with 2stroke motors but i get in the poo with the local constabulary when i build stuff that goes on the road...... thanks heaps in advance and i cant wait.. just a question im wondering if you might be local to me here on the Central Coast? a few of your videos have looked a lot like a place i have fished, would love to catch up and shout ya a beer if your keen and ive got a couple things you might be able to use.
Legend, mate. Love the videos. Im looking for a new auxiliary plus for small tender tishing, 3hp or 4hp Yamaha hopefully, in qld vessels 4hp or lower dont new license or rego. Really love your modified lower leg pickup
Hi Champion, Thanks for your encouragement 👍 Yamaha is a good choice for 4hp and lower. I believe the 4hp Mercury is the same as the 5hp just with one of the reed petal stops flattened so it restricts flow. Cheers 🍻 Aussie Boat Guy 😎
True mate. I’ve got further plans for that motor too. A modified gear case that is more hydrodynamic as the standard ones are terrible. It’s funny that the 6hp gearcase is shaped really well but the 5hp is a shocker. Cheers 🍻 Aussie Boat Guy 😎
Great video, thanks! Can you please confirm the standard prop for these is 7.8x7.0? I have a 2.7m Aurora RIB with the same Tohatsu 5 but with a 7.8x8.0 prop. Challenging to get this on plane & hoping the smaller prop will help?
I’ve a 8ft alloy punt, had a 5hp Mercury top speed was 31kmh with the tide, standard motor, 1 bloke. Dropped a 9.8hp on it and got 40kmh with 2 blokes in it on still water.
Hi mate, Sounds about right, I really want to try my mod 5hp on a light tinny and check what speeds I get. My mod 5 was about 5 to 6kph faster than the stock one on my heavy twin hull, hoping that is even greater on a light boat. I love the 9.8hp, such a great motor 👌 Cheers Aussie Boat Guy 😎
My 8ft punt is very light, the 5hp Merc had a 123psi on the cylinder. My 9.8hp Tohatsu has 150psi on each cylinder. Keep those vids coming mate, really enjoy the content!
Have you ever considered making an expansion chamber exhaust? Being that there's so much power potential in the exhaust system of a 2-stroke it would seem like the most cost/work effective modification.
Hi mate, I do think about doing that a lot, it’s just the fact that an expansion chamber is so large and would be external of all the covers and cowls plus the noise would get me in trouble where I live. maybe one day though. cheers 🍻 Aussie Boat Guy 😎
Hey man, enjoyed your video😀 You dont happen to know/remember the conrod lenght of that engine? I have a chinese copy by the brand of hangkai that just does not plane with two people in the boat, goes up fine with only one or a full grown adult with a child of like 10years. I am not going to alter the porttimings alot cause i dont want much more revs since it is quick enough as is👍 Great stuff💪
Hi Mate, I don’t know the conrod length unfortunately. Sounds correct with what the 5hp can push up onto the plane. Once I modified mine it does get two adults up on the plane but it really was a lot of work, honestly better off getting an 8hp, way smoother too. Cheers 🍻 Aussie Boat Guy 😎
@@25hpboatracerman I already have the engine in pieces now and now the portwork begins, was hoping to calculate some durations with the conrod length but I guess my previous experience has to be enough😀 not going to do anything crazy, the good thing about the Hangkai is the quality of everything(did not think i would ever say that about a Chinese copy🤣) the cast seems better than the tohatsu you had and that really surprised me. Just waiting for the jets now and some new gaskets and a new head with the sparkplug hole in the center so that i can fit it in the lathe👍 Many thank you from Sweden😀
Hi mate, I have been using a rev counter for most of the modified 5hp videos, if you check the later vids on that modified 5hp when I’m running it on the small aluminum boat it saw over 7600rpm and nearly 50kph top end speed. cheers 🍻 Aussie Boat Guy 😎
Another great vid.. can actually see the difference. Unsure if it may be better to get the 6hp and put the 5hp cowling on it, but look forward to the build.
Hi mate and happy new year 🎆 Hope your Christmas was awesome 😎 Absolutely, you are correct, a lot of work for a little bit more action. The 6hp tohatsu and Mercury two strokes are twin cylinder and weigh in at an extra 5kg, just wanted to play with the single cylinder to keep it simple, plus I had a shelf full of parts 😂 Definitely the 4 stroke you would change the cowl if you needed a 5hp. I may see what I can get out of a 9.8hp Tohatsu as well as they are only 25kgs which is nice and light where the 9.9hp - 15hp go to about 41kgs. Cheers mate 👌 Glenno
@@25hpboatracerman yes that 9.8 tohatsu is a great motor and if you can find one would make for some great vids. Thankyou I hope you had a great Christmas and have a enjoyable new year with lots of boating.
Cheers mate Yeah true for rpm. I was just looking at speed with this one. I need to get another mini tachometer for this stuff. Thanks Aussie Boat Guy 😎
@@25hpboatracerman to measure the result of the improvement in statics, we use a mulinette, you can make it yourself from an old propeller, or by measuring the thrust with a scale, I'm waiting for new experiments
Yeah, I had 11-12knots for the first one and 15 for the second. So, a bit high I think on the second one. But I sometimes take my friend's homebuilt and heavy wood dink out with a 8hp on it and I can get that to 13knots, and the first looked a tad slower. Will probably build a fiber on ply 12 footer soon as light as makes sense and try to track down a 9.8 Tohatsu 2-banger. That would be my dream boat for hitting up the local reefs for a bit of spearing.
Not bad guesses mate. I reckon the 9.8 tohatsu is one of the best little motors around, if you can get one I would. Good plan on the fiberglass boat. All the best, Aussie Boat Guy 😎
Why didn't you just go and buy a 6 horsepower.My suzuki 6hp 4smoke gets 17.3mph. Using a cut down sharpened standard propeller in a very unera dynamic sib .
That’s funny 😂 and I agree but - I’ve got bigger motors already and tinkering with it was the whole point. I’ve have an 8hp that did 19.4mph on the same boat. You have done the exact same with your 6hp by cutting down and sharpening your standard prop, then someone saying why? you should have just bought an 8hp. Answer = because it’s fun 🤩 I still need to play with props for it, engine hight and gear case shape, I’m sure there is more in it. Seen the guys in Malaysia race the 3.3hp Mercury two stroke (super modified and with race props) getting nearly 30 mph, I love that stuff Cheers Aussie Boat Guy 😎
@@25hpboatracermanDef do a video on the modded outboard. Then Mount both and do a vid on twin engines. The props should really be upgraded for that. Have fun!
@@gbass7328 I reckon the modded motor needs another 1 inch pitch on the prop now. Unfortunately I can’t mount both motors at once on that hull. Cheers Aussie Boat Guy 😎
@@25hpboatracerman Most pitch changes go by 2" at a time and that would give you the speed. I am seeing prop guys make shop pitch adjustments of up to 2" as a mod too lol. It would take a lot but I'm sure that hull could get modded to to accept them both. Anyway, cool!
Thank you, most impressive!
looking forward to further improvements.
the prop balance actually works.
keen for the run down on the motor and how you did it
Yep, will get a vid together mate 👌
Cheers
That looked alot faster, looking forward for the next video.
Cheers mate, coming soon.
👌
Awesome content as usual man! Cant wait for the build video. Greetings all the way from Trinidad and Tobago!
Thanks mate, it was a fun build and video. Wow 🤩 all the way from the Caribbean, awesome 😎.
Cheers
Aussie Boat Guy 👌
im actually super keen for the mod video as i have 2 of these beut little motors. one will stay stock as im actually quite happy with it stock and i get about 27ks out of my little savage gull (11ft Tinny) on my own with a little bit of gear. on a 7.8 x 8 prop. the other is in bits but i just picked up the last bit to put it all together (needed a gearbox) also have a new 7.8 x 9 prop for it and im really wanting to get every last drop out of it just for kicks. i love playing with 2stroke motors but i get in the poo with the local constabulary when i build stuff that goes on the road...... thanks heaps in advance and i cant wait.. just a question im wondering if you might be local to me here on the Central Coast? a few of your videos have looked a lot like a place i have fished, would love to catch up and shout ya a beer if your keen and ive got a couple things you might be able to use.
awesome mate runs and goes likes a champ u should try with 9.8hp or 15hp mate great video. And a happy new year buddy.
Happy new year mate 🎆
Yeah, it runs well. Exactly what I was thinking about doing - 9.8hp - 15 - 18hp 😃
Cheers
Aussie Boat Guy 👌
@@25hpboatracerman Grab a Nissan 8hp and do that one, I would love to see the results!
@@rrrttt1112
Yep, same as the 9.8hp, will do it when one comes my way 😎
Cheers 🍻
Looking to do some work on a 4 stroke 5hp. Probably port work. Carburetor. Might shave the head. It needs rebuilt anyway. Good video.
Hi Mate,
Thanks for your comments 👍
Sounds like fun and please keep us posted with your results.
Cheers 🍻
Aussie Boat Guy 😎
I always enjoy your postings
Thanks mate, really appreciate your comments. I enjoy making theses sort of vids too.
Cheers
Aussie Boat Guy 😎
Legend, mate. Love the videos.
Im looking for a new auxiliary plus for small tender tishing, 3hp or 4hp Yamaha hopefully, in qld vessels 4hp or lower dont new license or rego. Really love your modified lower leg pickup
Hi Champion,
Thanks for your encouragement 👍
Yamaha is a good choice for 4hp and lower.
I believe the 4hp Mercury is the same as the 5hp just with one of the reed petal stops flattened so it restricts flow.
Cheers 🍻
Aussie Boat Guy 😎
Quite a difference hey! It'd be interesting to find some way to hook the engines up to a dyno so you can see how much more power you're making.
True mate.
I’ve got further plans for that motor too.
A modified gear case that is more hydrodynamic as the standard ones are terrible. It’s funny that the 6hp gearcase is shaped really well but the 5hp is a shocker.
Cheers 🍻
Aussie Boat Guy 😎
Great video, thanks! Can you please confirm the standard prop for these is 7.8x7.0? I have a 2.7m Aurora RIB with the same Tohatsu 5 but with a 7.8x8.0 prop. Challenging to get this on plane & hoping the smaller prop will help?
Hi Champion, sorry for the delay in getting back to you.
From my experience the standard prop is a 7.8 x 7 .
Cheers 🍻
Aussie Boat Guy 😎
I’ve a 8ft alloy punt, had a 5hp Mercury top speed was 31kmh with the tide, standard motor, 1 bloke. Dropped a 9.8hp on it and got 40kmh with 2 blokes in it on still water.
Hi mate,
Sounds about right, I really want to try my mod 5hp on a light tinny and check what speeds I get. My mod 5 was about 5 to 6kph faster than the stock one on my heavy twin hull, hoping that is even greater on a light boat.
I love the 9.8hp, such a great motor 👌
Cheers
Aussie Boat Guy 😎
My 8ft punt is very light, the 5hp Merc had a 123psi on the cylinder. My 9.8hp Tohatsu has 150psi on each cylinder. Keep those vids coming mate, really enjoy the content!
Thanks for the video, love them 👍😀
Thanks mate and happy new year, hope it’s a great one for you.
Cheers
Aussie Boat Guy 😎
Have you ever considered making an expansion chamber exhaust? Being that there's so much power potential in the exhaust system of a 2-stroke it would seem like the most cost/work effective modification.
Hi mate,
I do think about doing that a lot, it’s just the fact that an expansion chamber is so large and would be external of all the covers and cowls plus the noise would get me in trouble where I live.
maybe one day though.
cheers 🍻
Aussie Boat Guy 😎
Hey man, enjoyed your video😀
You dont happen to know/remember the conrod lenght of that engine?
I have a chinese copy by the brand of hangkai that just does not plane with two people in the boat, goes up fine with only one or a full grown adult with a child of like 10years. I am not going to alter the porttimings alot cause i dont want much more revs since it is quick enough as is👍
Great stuff💪
Hi Mate,
I don’t know the conrod length unfortunately.
Sounds correct with what the 5hp can push up onto the plane. Once I modified mine it does get two adults up on the plane but it really was a lot of work, honestly better off getting an 8hp, way smoother too.
Cheers 🍻
Aussie Boat Guy 😎
@@25hpboatracerman I already have the engine in pieces now and now the portwork begins, was hoping to calculate some durations with the conrod length but I guess my previous experience has to be enough😀 not going to do anything crazy, the good thing about the Hangkai is the quality of everything(did not think i would ever say that about a Chinese copy🤣) the cast seems better than the tohatsu you had and that really surprised me.
Just waiting for the jets now and some new gaskets and a new head with the sparkplug hole in the center so that i can fit it in the lathe👍
Many thank you from Sweden😀
Great series of videos but you need a rev counter
Hi mate,
I have been using a rev counter for most of the modified 5hp videos, if you check the later vids on that modified 5hp when I’m running it on the small aluminum boat it saw over 7600rpm and nearly 50kph top end speed.
cheers 🍻
Aussie Boat Guy 😎
Sounds like you could do with a 1/2"-1" more pitch on the prop...overspeeding
Absolutely and I’m on to it, just wanted to compare to a stock motor with the same setup.
Cheers
Aussie Boat Guy 😎
Do a vid of one engine full forward and one full reverse and then see how fast it gose in reverse
Hi Mate,
That would have been a good idea but unfortunately I don’t have both those motors anymore.
Cheers 🍻
Aussie Boat Guy 😎
Another great vid.. can actually see the difference. Unsure if it may be better to get the 6hp and put the 5hp cowling on it, but look forward to the build.
Hi mate and happy new year 🎆
Hope your Christmas was awesome 😎
Absolutely, you are correct, a lot of work for a little bit more action. The 6hp tohatsu and Mercury two strokes are twin cylinder and weigh in at an extra 5kg, just wanted to play with the single cylinder to keep it simple, plus I had a shelf full of parts 😂
Definitely the 4 stroke you would change the cowl if you needed a 5hp.
I may see what I can get out of a 9.8hp Tohatsu as well as they are only 25kgs which is nice and light where the 9.9hp - 15hp go to about 41kgs.
Cheers mate 👌
Glenno
@@25hpboatracerman yes that 9.8 tohatsu is a great motor and if you can find one would make for some great vids. Thankyou I hope you had a great Christmas and have a enjoyable new year with lots of boating.
How many actual horsepower does the modified motor put out?
Hi Mate,
I would only be estimating but it would seem close to 7hp.
Cheers 🍻
Aussie Boat Guy 😎
Doe these little 5 hp outboards hve rubber hubs?
Hi Champion,
Yes, rubber hub in the standard prop.
Cheers 🍻
Aussie Boat Guy 😎
Awesome video 👍
Cheers mate 👌
Really appreciate it 😎
hi, good job, for a more accurate measurement of the result you need to get a tachometer
Cheers mate
Yeah true for rpm.
I was just looking at speed with this one. I need to get another mini tachometer for this stuff.
Thanks
Aussie Boat Guy 😎
@@25hpboatracerman to measure the result of the improvement in statics, we use a mulinette, you can make it yourself from an old propeller, or by measuring the thrust with a scale, I'm waiting for new experiments
@@ЛодкииМоторы-ж1и
Yeah nice 😊
All the best mate
Cheers 🍻
Aussie Boat Guy 😎
I need to see how you modified!
Yep, video coming.
It was a big job, not just bolt on easy stuff unfortunately. So much fun though 😎
@@25hpboatracerman i can wait to see it! I have yamaha 5m model 1990 .. little difered but i hope you can inspier me
@@25hpboatracerman i am already ready to big jet but i think i might bore the air intake and exhaust two
@@25hpboatracerman i will also put a modified atomizor from 8 holes to 30 holes
@@_.R.F.X.L._
It’s a fun project and I would be interested to see how you go with the Yamaha 😎
Would you estimate the HP is up much? Like maybe 8?
Hi Mate,
I would estimate like 7hp but it’s faster because it is capable of high rpm because of the way it’s ported.
Cheers 🍻
Aussie Boat Guy 😎
how heavy is that boat`?
Hi Mate,
It’s actually pretty heavy for a dinghy, it’s about 55kgs.
Cheers 🍻
Aussie Boat Guy 😎
How can you get 25kph with a modified 5hp when I struggle to get 25kph with a 15hp! 😓 exactly the same hull all I have is a front casting deck
Yeah, heavy little boats.
Not sure what is going on with your speeds. I was surprised how even the stock 5hp went.
Cheers 🍻
Yes it's worth it
Hi Mate,
Agreed 👍
I was surprised at the difference it made modifying that little motor.
Cheers 🍻
Aussie Boat Guy 😎
How many RPMs did it go up with the mods?
Hi mate,
Not too sure but would be around 800.
I should check with a tacho.
Cheers 🍻
Great video mate!
Cheers mate, I really appreciate your comment.
Thanks,
Aussie Boat Guy 😎
Haha i guessed 12 knots on the first run. Then 14 on the second.
Wow, that’s a very good guess mate 👌👌👌
Cheers 🍻
Yeah, I had 11-12knots for the first one and 15 for the second. So, a bit high I think on the second one. But I sometimes take my friend's homebuilt and heavy wood dink out with a 8hp on it and I can get that to 13knots, and the first looked a tad slower.
Will probably build a fiber on ply 12 footer soon as light as makes sense and try to track down a 9.8 Tohatsu 2-banger. That would be my dream boat for hitting up the local reefs for a bit of spearing.
Not bad guesses mate.
I reckon the 9.8 tohatsu is one of the best little motors around, if you can get one I would.
Good plan on the fiberglass boat.
All the best,
Aussie Boat Guy 😎
Why didn't you just go and buy a 6 horsepower.My suzuki 6hp 4smoke gets 17.3mph.
Using a cut down sharpened standard propeller in a very unera dynamic sib .
That’s funny 😂 and I agree but -
I’ve got bigger motors already and tinkering with it was the whole point. I’ve have an 8hp that did 19.4mph on the same boat.
You have done the exact same with your 6hp by cutting down and sharpening your standard prop, then someone saying why? you should have just bought an 8hp. Answer = because it’s fun 🤩
I still need to play with props for it, engine hight and gear case shape, I’m sure there is more in it.
Seen the guys in Malaysia race the 3.3hp Mercury two stroke (super modified and with race props) getting nearly 30 mph, I love that stuff
Cheers
Aussie Boat Guy 😎
Modified reaches 25% higher rpm hearing the pitch increase.
Yeah, I reckon it does.
I should put a tacho on them and see the difference.
Cheers 🍻
Aussie Boat Guy 😎
@@25hpboatracermanDef do a video on the modded outboard. Then Mount both and do a vid on twin engines. The props should really be upgraded for that. Have fun!
@@gbass7328
I reckon the modded motor needs another 1 inch pitch on the prop now.
Unfortunately I can’t mount both motors at once on that hull.
Cheers
Aussie Boat Guy 😎
@@25hpboatracerman Most pitch changes go by 2" at a time and that would give you the speed. I am seeing prop guys make shop pitch adjustments of up to 2" as a mod too lol. It would take a lot but I'm sure that hull could get modded to to accept them both. Anyway, cool!
But you are right. For a small prop, 1" difference will be similar to a 2" change on a bigger prop.
20
Yeah, not bad 😎
My 6 hp goes 20
That’s not bad, what boat and what weight on board?
cheers 🍻
Aussie Boat Guy 😎