Homemade Jet Drive 2 Stroke Twin , Board Building

[@DktheWelder]

The files for this are free on CG Trader www.cgtrader.com/products/100mm-jet-unit-no-intake-for-free

[@jlucasound]

Metal Shaping is an absolute Art. Taken for granted with the CNC forming in the auto (etc.) industry. To do it by hand is really tough. You have done well. Very well.

[@BruceLyeg]

I have no suggestions. This is an awesome project. There isn't much that you can't make. You have some serious fabrication skills.

[@DktheWelder]

Thanks Bruce

[@dallas749]

You gain a small percentage of thrust with the jet above the water line, the water slows the rate in which the stream can accelerate out. It doesn't need to bounce off water its a jet.

[@kansaIainen]

Exactly! You can test this using bathroom shower: much more efficient if not pushed in a bucket full of water.

[@darrelgreene]

Fluid dynamics get tricky but some playing around with the weight distribution and displacement will help... BUT... Man, you need lots and lots of Torque to keep that water moving out of that nozzle, and exponentially more and more and once the vessel is on plane or "out of the Hole" but at speed you'll get a better idea of any change needed in angle of attack of the exit nozzle to the water line.

[@Alex-xh1zi]

Jet should exit just above the waterline when on the plane for maximum efficiency

[@brucebaxter6923]

Ok. Old guy been playing jet boats for many years. Jet goes over the water line when running, and under the water line when stationary to prime it. As for couplings, don’t underestimate the effectiveness of the rubber and cloth fuel transfer hoses with a hose clamp or two at the ends. As for couplings between the motors, O rings or silicon tube over (bolts) printed columns give shock absorption and wear resistance. Keep up the great work, I am so impressed with what you are doing.

[@markcurtis3791]

Mean to see the bros helping each other out . Dan I reckon that when u lie on the board and open up the throttle ur gunna rip ur togs off and damage your crown jewels.

[@DktheWelder]

I made it kinda big so I should be able to stand on it while still. I hope doesn’t rip my togs off!

[@impuls60]

You might try a armored hose as a shaft coupler instead of a 3d printed one. Keep up the good work!

[@DktheWelder]

Yes I really like that idea! I can use hydraulic hose, thanks a lot 👍👍👍

[@Mad.Man.Marine]

I was just gonna say hydraulic hose works great. I have had good luck with it on way more power then this. So you should be tit!!

[@daviddelosier1915]

I have used a 4 wire hydraulic hose on water pump. You can also have the hydraulic shop crimp your couplers in for you. ( By 4 wire hose, I'm it has 4 layers of woven wire reinforcement wire in it)

[@kwerk2011]

I used to do all the 3D visualisations for Hamilton Jet's demo videos. I'm not an engineer, but I was always asked to have the nozzle right at the waterline (half in, half out) whilst the boat was not moving. Best of luck!

[@doc-holiday]

Looks good i cant wait to see the final board in the water fully working. Keep up the great work.

[@DktheWelder]

Thanks 👍

[@84OldsHurst]

Love the use of 3d printed tools and surprised they worked so well! Keep it up, it's looking awesome.

[@DktheWelder]

Thanks yeah they did work awesome

[@bocian85]

yeah to easy align them you could use magnets on both parts so they would pull to the center by themselves

[@tasken92]

you should mount the engine on rubber mounts to take away much of the vibrations. also, i still think TPU could be good way to transfer power from engine to the jet unit. like 3 part coupling with TPU in between for taking upp some misalignment and also some dampening! cool video, looking forward to next update :)

[@miked5444]

Was gonna say this too. Not only that the layer strength on TPU is insane.

[@brucebaxter6923]

To print multiple materials on a single head machine, Slice the parts separately and change bed coating thickness to match each material start point.

[@homemade_madness]

Loving the project dude!

[@DktheWelder]

Thanks 👍

[@SamBarker]

Great work Daniel, given me motivation of all sorts of projects now! Look forward to more

[@DktheWelder]

Thanks. I’m a big fan off your channel , after watching that hydrofoil video I want to do the same but with a longtail motor

[@shannonm3841]

i learned airframe work in the Air Force so cool to see most of those skills alive and well in use in this video, reminded me of building a Leading edge for a C-130 wing minus the ribs and stringers

[@B.Cote39]

Excellent work man ! Keeps a fella from giving up on crazy hard projects! Thabk you !!

[@beehphy]

I think it looks sweet! Don't change the back. Having the jet above the water means little. The water jet is your thrust, and just like a proper space rocket it doesn't matter what happens to your exhaust once you throw it away. A rocket doesn't need the ground to push off of and you don't need water to push off of. So long as you can feed the pump and aim the thrust, you're set! Good show!

[@KarlsKrafts]

You want the jet lower than water when resting. If it isn't, it's full of air and you need to move enough air to suck the water up and prime the jet. Air has very little resistance so to pull the water you need to move a lot of air to pull the weight of the water. Once the jet is primed it can easily suck more water up as the water has resistance, mass, and momentum and won't flow backwards as easily through the impeller. Then every time it breaks suction and gets air in it(light chop on plane can be enough for this) it will need to do this all over again. Using an impeller that uses centrifugal force to compress the water works much better than one modeled after a boat prop(don't know which you used).

[@offgridas]

My brother has a uv resin printer, quick as, and craaaazy detail. One of the resins he has is not that strong, but another blue see through one is super strong, hit a test bit with a hammer quite a few times before it cracked

[@DktheWelder]

The resin ones are really cool , that PLA die I hit it like a thousand times and it held up fine it certain situations it is strong

[@AtimatikArmy]

I race jetskis and also wondered if it matters if the nozzle is above the waterline. Although it seems like you would gain thrust by having the jet blast push against a denser material, apparently that makes no difference at all. As I understand it, it's the inertia of the water that's being accelerated out the back is what causes the opposite but equal reaction moving you forward.

[@Mad.Man.Marine]

I was always told you are actually pulling yourself through the water. Not pushing when using a jet pump. But also. As far as Nozzle height. The way he has it is exactly how all jet-skis are made. That’s the job of the ride plate. He just built his right into the hull.

[@n00bkill]

As a suggestion, you may be able to make a coupling by welding a hex head socket onto a bit of tube. I can't remember how the prop shaft from your impeller is terminated, but it shouldn't be too difficult to couple it to a tube. Amazing work as always!

[@wilcootten9516]

Try printing the shaft coupler horizontal so u have single connections from one end to the other instead of stacked connections

[@duncanb1981]

Jet unit above the waterline. This is what Hamilton did to make an old invention that we know today as the Hamilton jet work. Above the waterline allows more flow of water through the unit as there is less back pressure. It is the weight of the water that you move that propels you forward.

[@DktheWelder]

Yes the Hamilton jet was invented here in New Zealand 👍

[@theideasman6018]

He'll yeah BROTHER that looks like some fun

[@fazyluck]

Hell Ye man! Solid progress! Busted out the Dimple die even! 🤙🏼

[@DktheWelder]

Thanks for the help👍

[@ifnotnowwhen6914]

If you think you'll be doing more shaping like that, might I suggest an English wheel. Even a homemade one can do some amazing (and surprisingly quick) shaping. Very entertaining video, looks like fun.

[@poisonouspython1410]

set screws on carb collars, silicon material to sandwich on engine mounts, you'll have it ripping on the water in no time

[@DktheWelder]

I like your thinking! Good ideas

[@DatBlueHusky]

also dont listen to the people saying you need the nozzle in the water, they dont own a seadoo/jetski. My seadoo when at full power doing 77kmh, the nozzel is fully outside of the water blasting at the back few feet before hitting the water

[@DktheWelder]

Yeah it just works by throwing the mass (water) back pushing it forward . I just hope people read the comments like yours helps everyone learn a bit more👍

[@morphshag]

this is cool man I haven't see your videos before, I like the old school metal work mixed with 3D printing to reach the end result you're after. pretty cool..

[@gabbermaikel]

most jet boats and jet skis have the jet only in the water at low speed. I think it can improve the low end efficiency a bit. But as soon as you get up to speed all of the tend to lift the jet outlet out of the water as far as i know. There is now way to keep the nozzle under water if you are up on plane with a boat. So if it didnt work like that then a jetboat couldnt be on plane ever.

[@trickywoo356]

Awesome build - my favourite kind of entertainment to watch, good music too!

[@tazyt3388]

Great test mate fail points found modifications coming soon luv it cheers

[@DktheWelder]

It really wasn’t ready for a test but it is good for finding the weaknesses 👍

[@tazyt3388]

@@DktheWelder that’s it mate I bash crap outa my builds around the farm before they go bush it’s good to know the weak links it’s guna be a fun toy mate

[@jlucasound]

You will get it. Hey! Uploaded on my daughter's Birthday! :-)

[@mangsonicr3152]

I have wanted to do a twin with these engines for about ten years. You are the man! Thanks for sharing this with everyone! I have used these carbs/reed blocks on pocket bikes, they fall off no matter how tight you clamp them, almost like the intake is slightly tapered. I have used some red RTV on the reed block before i clamped carb back on and it never fell off again! Maybe worth a try.

[@DktheWelder]

Ok that sounds good I will try that 👍

[@phildawe7172]

Waterline jet nozzle: the nozzle above the water line should work just fine. My gp1200 is above most of the time. One can clearly see the thrust column of water before it re emerges. As long as the intake is scooping that's good. Amazing job of the shell so far. Zero rubber enging mounts/dampening... hope it stays firm. Good work so far

[@Eden_M]

YES, Same Page Club.

[@jaredpursey3791]

I'd say print 2 outlets, one with under the water and one how u have it now just at a 45 or so. With the mix of the 3 options u will have I'm sure u will figure out what feels good Jet wise.. but that's down the track mate. Don't worry about that stuff until u can get through a test run without something rattling loose or blowing up on u. Really interesting concept, I've been thinking on a 3cyl engine for a pocket bike, but running N-S not E-W with a 90° "gearbox"

[@DktheWelder]

Yeah I think you could run 3 cylinder it would sound awesome, I was thinking it might snap the crank on the last motor but I guess if they aren’t firing in sync it should be ok 👍

[@jaredpursey3791]

@@DktheWelder for what $50 for a new motor I don't think I'll stress about a broken crank on a death $150 death machine 😂

[@carnivorecave]

This will make an awesome RC Boat...

[@MrGuitarguyadam]

The people saying that the jet needs to be below the water line… don’t really know how a jet pump works. The water out of the jet does not have to hit anything in order to propel the boat forward.

[@DktheWelder]

Exactly, there are still people saying it should be underwater I don’t understand why they think that

[@michaelquiltysherwood9615]

very interesting idea / design cant wait to see it get going, i have tried dealing with these engines in the past and had similar issues, with the carbs i ended up having to put thread tape between the round manifold and carb and filling the clamp gap out a bit for more grab to get them to stay on but what i ended up doing was making a manifold to mount a wallbro two needle type carb on and that worked way better, thank you for the top and bottom beading die idea i might have to give that a go, and im also impressed that youre able to weld 1.6 ali im working on something similar and wasnt even gonna bother trying it lol might have to now

[@DktheWelder]

Thanks, you can weld 1.2mm aluminium as well . I think bigger carbs would make a bit of power increase too

[@michaelquiltysherwood9615]

@@DktheWelder yea im sure its possible i just hate welding ali, thinest ive ever welded was 0.6 but that was stainless, the reasons i went with the walbro carbs is they are way easier to tune and better quality and als they are what i used in high performance 1/5 scale rc cars and i know they can make big power, i bought two of those motors at the same time and the ones i got were only a few serial numbers apart so same batch but the jets in the carbs were different sizes along with a few other things i noticed along the way so i think that speaks a fair bit to the quality of these

[@AtimatikArmy]

Just make sure whatever carbs you go with that you have no air leaks! It will never run right but more importantly is that an air leak is the death of a 2 stroke. The Chinesium OEM carb mounting setup is telling me that you are going to be having air leak problems. If it starts revving high at idle with the butterflies closed, you'll know you have an air leak.

[@spencer9854]

Is the motor solid mounted if so might want to use some rubber to dampen down the engine vibration

[@andrewostrelczuk406]

There are small diameter commercial made couplers. I have a few on small gas engines to Pumps they have a Hex screw that fastens 1/2 of it to the drive shaft then a rubber shock absorber and the Mated second 1/2 to the Driven shaft also with a hex screw or Allen screw. Seems like the distance between the impeller shaft could be better taken up by a small “Jack shaft” in cars or trucks more often and military equipment they have universal joints at both ends allowing a change in drive angles. If you were to put the nozzle output below the waterline a great way to couple the shafts would be this way. I’ve found couplers like described above at hardware stores. It’s 20°F on this winter day up here in Michigan. -6° C, and Sunshine on this second day of the year!

[@GY6-SCOOTERS]

I'm diggin your boat project looks good bro ...👍

[@RickyJay-zs4ix]

Love the idea but I would have made the board out of foam stiyren and then coated it with marine fiberglass but keep the aluminum engine bay as an insert! This way it would be easier to manufacture ,easier to service and won't have to worry about leaks ! I was an aircraft structure ( fiberglass) mechanic in the Navy! You will be on that TV show and you will make more money than the people who made the seadoo!

[@RickyJay-zs4ix]

I was wondering do you have the geode for the connector from the output shaft to the cooling fan! Give it to me and I will forge it in aluminum and ship it to you as a favor

[@starlordd6408]

Totaly Legit!!! I have been printing for 5+years now and I absolutely love the way you are making those tools. Are you hosting your 3d files anywhere?

[@DktheWelder]

Na I can email them to you if you want

[@darrelgreene]

I think you'll see your best results getting things setup right before the point of cavitation, so when your vessel is on plane... the top of the exit cone right at, or dead on your riding water line.

[@chriscoast2coast1207]

Thanks for sharing ❣️ Awesome idea back to the drawing board ❣️😎✌️🌉

[@jlucasound]

Your Boss is Awesome!!

[@luiscotto6659]

Some rubber bushings help with all the vibration causing things to break

[@DktheWelder]

I had the engine plate rubber mounted , but those motors are junk they are so out of balance. I think a better option are those bicycle engines with chainsaw heads on them 👍

[@gregsteele9002]

Ahhahaha Luv the Ford sander/polisher! I've just had the carb fall off of my minibike because I forgot to torque it down after cleaning. Luckily I only had to push/scoot it home < 1km to get my tools

[@andrewostrelczuk406]

As for the Armored Hose idea a piece of old Hydraulic hose could be the quick way for proof of concept. The only problem is keeping it tight on both ends. Hose clamps would work if some splines were on both shafts... even they can strip out the rubber and eventually they will!

[@jacquesdeklerk5563]

You have to have rubber engine mounts , you can't just bolt it to the alloy it will rattle things to shit. And water jet always above the water. It will actually perform worse underwater due to friction. I studied fluid mechanics you can trust me on that one. Its nothing to do with what the water exiting the jet comes into contact with. It's purely based on the mass of water the pump pushes out, and the velocity of that mass of water. I'd go with an actual uni for the driveshaft, it will drastically reduce the shaking and vibrations aswell.

[@DktheWelder]

Thanks nice to hear from someone with education on this I thought that is how jet pumps work best. I am trying to figure out a good rubber mounting idea I have some flexible filament for the 3d printer maybe i can print something

[@jacquesdeklerk5563]

@@DktheWelder I'd stick to just using some 5-10mm solid rubber so you know it won't fail. That's honestly why your carbs vibrated off so quickly. 😅

[@DktheWelder]

@@jacquesdeklerk5563 It could be because the mounting isn’t solid enough like all 2stroke dirt bikes are solid mounted , my last little jet boat didn’t have any vibration problems. I might be able to get the engines synced up smoother

[@jacquesdeklerk5563]

@@DktheWelder yeah but there's allot more structural integrity and rigidity to a bike frame compared to the flat sheets on the surfboard. Experiment I guess. I'd go with rubber all day. I even have rubber on my big rc boats and it slaps down the vibrations astronomically.

[@walterbargersr3402]

If you heat up the aluminum you can use the shrinker it will work much easier and better also remember around your motor you have to watch out for harmonics because it can crack the weld it would be a good idea to use rubber motor mounts for the engine also why I suggested Heating the aluminum because when you go to shape it or even put it in the English wheel it makes it more pliable

[@andersson.l.e]

This one is going to be good. Keep up the good work.

[@mikerammelt2420]

Cool work Cuz. Might be an idea to run a brace from side to side across the top of the engines to help with torque. Cool that the coupling held up. You could try rubber mounting everything and it would be cool if you could decouple the engine from the jet. Sending those harmonics to that coupling wasn't kind ☺️. Some sort of a CV joint would be perfect. Yeah, preheat the water before you stick it in, otherwise you'll get thermal shock on the parts and loose power. Henry Ford figured out that if you keep the water as hot as you can before it boils the more efficiently the engine ran. You can add and remove copper coils to the chamber's to get your exhaust water temp right. Yeah play with the water line nossel. Phone Hamilton's ask them. I see a guy that worked there said what the go is. Good Luck. Add Pop later. 😊

[@tylerwatts1004]

So cool! Wondering why you don't have any curvature or hull shape, the board is going to be rather unstable.and awkward to steer, unless you are fitting some fins to it? Jet is fine, should work on the physics of equal opposite reaction, chucking water out the back is what pushes you forward, not pushing against water. When a jet ski plains the jet is out the water... Don't jet it down or your trim will be wrong, in fact a slight trim up will probably help but you might struggle to make the trim accurate. Looking great, good luck with this build!

[@DktheWelder]

Just a flat bottom is good for surfboards my dad used to make surfboards he helped with the design a bit but I might need a fin to help it track and turn

[@jaredpursey3791]

Cheeky rodeo burnout for us😂😂😂 love it

[@johnnycolorado5481]

Try a Lovejoy coupler on the shaft, I think that would work perfectly for the desired outcome.

[@exoc1]

The jet should deffo go out just above the water line. Try next time you're sitting in a bath tub and hold the shower head in your hand and turn on the water, first do it under the water line and then hold it just above. The difference in force is very noticable.

[@kiwialex_photos]

haha this is looking awesome. Looking forward to when you get out in the water

[@DktheWelder]

Thanks Alex

[@maxpower700]

Jet outlet doesnt matte alot, since you are actually pulling the craft forward with the inlet, not pusging it with the jet👌

[@AtimatikArmy]

wrong

[@Eden_M]

I mean, a coin has two sides, so it's partially correct, without the inlet there's not outlet. but shooting the (accelerated water) jet stream underwater defeats the purpose of a jet.

[@floridamangonwild]

burnout master

[@clintonbeasy6609]

Good work man always fun to watch

[@soft-conf]

If you print the parts so the force goes perpendicular to the layer lines the parts will be much stronger.

[@mrpurcountry]

You should take a look at the bottom of a jet ski this will give you a good idea on the waterline and positioning of the jetdrive and your motor should be isolated on rubber mounts like they use on a chainsaw, and you should have a vibration dampener between the engine and the Jet Drive. You'll probably find you need to V the bottom from the jet drive intake out to the sides of your craft so the jet drive is lower than the waterline

[@andyjota8906]

Great project I cant help thinking a wipeout situation where it ends up hitting you in the back of the head ouch fugg that for a game of squaddies... where did you get the engine from?

[@davidblalock9945]

Y’all sure love letting the smoke out down there.

[@DatBlueHusky]

what i would do is start printing counter weights with the coupling in the middle and rotate it to see where the motor runs smoothest. Those cheap china pocket bike motors are horribly imbalanced. Ive balanced one by lighting the piston and how i did it was i dremel the inside skirt of the pistons to remove material

[@DktheWelder]

Another guy was saying how unbalanced they are they are , I’m running 180 apart I could change this maybe it would help it sounds tricky trying to balance them

[@murphyking79]

I can tell you from experience for power on takeoff nozzle in water will give you takeoff power. Nozzle just hitting the surface like ⅓ underwater will give you top speed. ½ in ½ out will give you best of both worlds.

[@leighsavage3267]

What if you build a box an do like a scoop from underneath the boat so when you get going it’s forcing water into the box witch you could run a hose off for cooling the jet drive. And might be worth making a metal bit to connect the to the drive shaft less problems being out of metal

[@jakebarnhill6308]

Looking good. The jet should be above the waterline like you have it. To speed up print times try a 0.6mm or 0.8mm print nozzle.

[@DktheWelder]

I might try that , also now I have the printer in a box in the shed and just leave it running all night which is great!

[@jakebarnhill6308]

@@DktheWelder that’s very handy! Just be aware that if the printer happens to fail and get hot, it could cause a fire being in a wooden box. I keep my printers outside over concrete so if they did happen to light up, they won’t start a fire.

[@floridamangonwild]

you could use a tarp in your truck

[@DktheWelder]

I was going to do that but it has too many holes haha I will buy another one for next time

[@noelwellstead8744]

I’m sure if you look at the jet ski you will find that the nozzle is under the water and the reason is 2 fold , steering and thrust. Also for better control ability you should add sponsons.

[@thelethalmoo]

really want this on my whitewater kayaks to fire off waterfalls

[@uninhabitablelakes_byruthl4240]

This is crazy I thought I was the only one doing this build... Everything is just about the same wow I need to ask you some questions I'm having some trouble.

[@DktheWelder]

I’m having trouble too but working through it , are you making the same thing?

[@jamie66233]

Under water with the jet for sure!

[@daddyfixit5188]

Look at high pressure water bilge pumps on boats. I’m talking tankers. They blast water through water to pump twice the volume twice as quickly. Same could b used here to create more power

[@AtimatikArmy]

Interesting thought. I wonder if that might actually work?

[@maxavssw]

You should build an amphibious reverse trike that looks like the 1000cc with a jet drive for water.....

[@jamesmccomb6217]

Skill saw with a new tungsten blade, way better for cutting Ali

[@DktheWelder]

I do that on long cuts but I have to setup a straight edge or I wander off the line haha .

[@TimsBitsnPieces]

Your soo lucky that your boss lets you use the stuff at work...

[@c42cly]

Above or below the water line will not change the thrust coming out only your drag would be affected. Water jets work on moving a mass of water out of the jet which gives you thrust Jet propulsion is a practical application of Sir Isaac Newton's third law of motion, which states that, “for every force acting on a body there is an opposite and equal reaction.” So the jet can give the same thrust I. Air or water?

[@spokster1]

If the coupler can take it, maybe some bits of rubber for the engine mounts, so it dont shake itself to bits

[@DktheWelder]

I think that’s what I need to do 👍

[@spokster1]

If you can get the rubber to flex more on the rotation direction of the engine, so if the jet drive loads up a bit much the engine can flex with it slightly so it doesnt try to twist the coupler

[@David-uy6ch]

Awesome

[@limitlessbuilds]

Nice work man! I am picking up my first 3D printer tomorrow 😬. Might help with a few difficult things coming up

[@DktheWelder]

Thanks. They are so cool and you would make so good stuff with it looking forward to see what you make

[@limitlessbuilds]

@@DktheWelder well nothing crazy planned, but some needed pieces for sure. You seem to use it all the time so will definitely be handy I’m sure

[@peterbaiter6880]

Rubber mount it . 2 strokes vibrate like crazy

[@BIGSMOKE-bl2lq]

Do a home made rubber cush drive thing for the coupling easy enough to make kinda like to gear box dogs facing each other with a rubber star in between them

[@jacquesdeklerk5563]

Just grab a steering wheel uni from the scrap car yard 😂 that's basically the same thing. Would cost nothing. Definitely needs to get a rubber coupler or an actual uni. Will never fail and also will not vibrate ☺️

[@DktheWelder]

A love joy coupling , I was going to do that but thought I would try something different

[@DktheWelder]

@@jacquesdeklerk5563 I used one of those on my last jet unit I thought I would try something lighter and easier.

[@Swaggot05]

Maybe change the 3d printed part on the drive to metal (with casting or milling) but if you can’t in the print settings of whatever modelling software you use there should be a infill density setting for example this changes the print from being maybe 20% plastic to sum thing like 50% or 60% plastic and a better plastic to use I called petg it’s much better than pla because it’s stronger and the layers stick better I thing it will be better for the application

[@djmjr77]

The jet unit should be midway in the water. If its totally above, depending on your draft, the pump won't be able to prime. If the pump doesn't prime try adding some ballast to the back of the board. When you come onto plane,, the pump will be mostly out of the water,, but by that time the pump is fully primed. Completely under the water is unnecessary possibly problematic.

[@djmjr77]

Def print everything solid also now that you have your prototyping done. Maybe even look into getting some stuff machined. If you want more vid content do some loss PLA casting with aluminum. This guy shows how to make a no frills furnace kzbin.info/www/bejne/hnyWdah4Zqmnq5o and there are a ton of other vids that show how to make the propane torch part. Good luck! The board is looking awesome!

[@bhankutoe6647]

i like it man.

[@plushterry627]

looking good. might be worth putting some sort of snorkel on the air intakes for the final version

[@narramoresolutions6398]

It’s above the water line when your wide open any way ;)

[@Sawsquatch]

When the exhaust pushes harder than the jet! 🤣🤣🤣

[@BIGSMOKE-bl2lq]

Try a 125-250cc 2 stroke dirt bike motor cut the the gearbox off make a pull start drum thing off flywheel side and a coupling welded to the gear off the crank be way better that the china motors

[@jacquesdeklerk5563]

The whole project is around the china twin, so by replacing them will kinda be like removing the foundation of the project though 😅

[@BIGSMOKE-bl2lq]

@@jacquesdeklerk5563 it will be removing the the lowest quality part i think he went with em cause there small but with what i said and some exhaust modifications and a 90° elbow on carb intake youd get that pretty slim as well also power torque reliable etc

[@AtimatikArmy]

@@BIGSMOKE-bl2lq Why just go with a 125 or 250? Might as well drop a 500 in there, or maybe Chevy 350.... No, no, no he needs to drop in a fully built up Chevy 454... Well except it would be bored and stroked and no longer a 454... You get what I mean! I guess that means he's building an off shore cigarette race boat now.... you know... apples and oranges... I say go pomegranate.

[@fairwind8222]

What is that two stroke? Cool engine

[@scotrtoonzes1110]

For when you gotta herd the elk to the other side of the ridge. Or fish into another lake.

[@Naferner_Said]

you couldve hammered the aluminum, and stretched it faster. use a block of wood under neath the hammer, so you dont leave welts in the metal. cut down a cv axle for the outboard prop to drive the jet drive. itll handle the G's better than that corn based plastic will. also if you make your water jacket larger, you can increase the flow of the water. betchya shell fly then n yea under the boat will do better. otherwise you ride under the water line.

[@HugoHugunin]

Water is non-compressable and air is compressible. A jet of water pressing against water will give many times the power of air.

[@bamoblivion8614]

Probably better off using those 3d printed parts to make aluminum ones by sand casting

[@Semparo]

might be able to use some heat shrink tubing for the carbs to give em a bit more grip! that's the only idea i have for this lol

[@Semparo]

or carve a groove with a file or some sort of grinder and use a o-ring o.o

[@jameskellow8001]

What plastic were you using for the line punch

[@DktheWelder]

Just PLA 100% infill after all the hammering it wasn’t even marked worked well

[@iamkian]

Nice.. I want to learn how to weld aluminium.... Could be so handy for me later :-) And Yes. jet should be about 2/3rd underwater for best performance!