Thanks! I’m a big fan of your channel , I actually don’t really know what I’m doing with the jet units but think I’m on the right track. I am happy to help out any way I can 👍

@@DktheWelder akm

Thanks I glad someone got a laugh out of it

Thanks 👍 I watch both those guys!

Haha it sounds pretty cool

@@DktheWelder mgqgaVva qmam v

Cool mini inflatable boat sounds fun

Where can I get my hands on some little motors like these? Which website?

@@davegibs4761 i got mine from ebay, £39.

Chainsaw motors are pretty powerful I think you need at least 6-7 hp to get up , I have a big stihl chainsaw I but on a surface drive on my channel which was fast. Maybe an 80mm impeller would be enough? I hope you get to making it!

Haha I had to leave that in , it was a struggle to turn them off

That could be an idea, it is all very well running this on a bench but under load it could be a different story

@@DktheWelder Three upgrade i recommend for this setup. First as i say - Y shape intake. Second: use soft coupling between engines. When i was buildet my device i use very hard rubber disk with four holes as coupling element and two disk with two cylindrical fingers as input and output. And three - i use ball shape joint to connect exhaust pipes. Also very important right setting of pistons before connecting engines. One must be at top position another on bottom. First time i missed that. And when my device start - i got jumping crazy frog :)

Thanks Bruce

Thanks. I’m glad it works, building the board will be fun

@@DktheWelder will be a handful

Thanks 👍 Colin furze is the man haha

O cool! I am actually building a chainsaw powered longtail motor for a kayak sized boat at the moment. A few things to know though, a kayak isn’t a planning hull so will just plow water instead of getting up on top, and jet drives suck the power like they need double the power a prop does to go the same speed, really manoeuvrable though

@@DktheWelder ive heard that about the problems with the hull shape, my plan is more or less to apply the power first, expect the boat to behave like it hates it, and start messing with strakes or maybe some sort of trim tab if i can keep it simple. I did not know that about the jet drives, its a good thing i havent made my final selection for a power unit. Thanks for the advice, and you do some fantastic work homie!

Ok thanks I think I will try that

@@DktheWelder late to the party, but drop retractions, too if you can - they can leave leaky pin holes. As for PLA being "best", well if best = easiest, then yes. But not in terms of heat resistance or much else.

Haha not much science, a lot of trial and error

I was hoping to print a fuel tank but I don’t think that is going to work 👍

@@DktheWelder look into PETG, it prints easy like pla and could be used for a gas tank. I've used PLA as motor mounts on a go-kart and they lasted a long time but showed signs of dissolving. So that's the only thing I'm basing my evidence on, you could print a test gas tank or drop a piece of a print in some gas and see how it fares. Good luck!

Thanks! Colin furze is great haha

Hydro forming it’s very cool I have actually tried it before! It’s difficult not to get any creases and curves get distorted it’s ok for bigger stuff but I would mess it up I think

It does sound pretty cool in person

Haha yes ! And thanks

You might not know this but this IS part two. Check the video right before this for part 1

Sorry I work full time and have kids and stuff, hopefully next week or the week after

Fair enough bro. Love your content man. I tried the same engine set up 2 years ago behind a 89 wave runner (wr500) jet unit, it didn’t go so well as i used the really cheap units that come on the common Chinese kids bikes.

It isn’t the strongest way of making stuff but is good for some stuff

@@DktheWelder Definitely. I like the way Rocket Lab 3D prints their rockets. ;)

I'm trying to build this board for under $1000 dollars I hope it works!

@@DktheWelder that's rad. I reckon you can do it! working out the hull/board will be interesting. fully manufactured from aluminium would be rad. or a hybrid foam/exo-fiberglassed shell with aluminium mounts for the engine and jet 🤔 also want the exhaust to not draw in water from backpressure. use whatever trick outboar motors use i guess. keep it up! :-)

It didn’t really work that well not enough power. Have you seen the test video?

@@DktheWelder I wanted to use 4 ms290 chainsaw motors

Haha Allen Millard would have done a way better job!

Thanks 👍

I did think about the copper pipe thing but I reckon I can weld a jacket on the cylinder. But I might wrap some copper pipe around the exhaust to try cool it down a bit

I hope so! If the expansion chambers are right it should do

ok I will try find one thanks

They are at 180 degrees apart, it does sound awesome just not very powerful 👍

@@DktheWelder Thank you. I'll be building my own! Twin 2 strokes are rare as heck, this is gone be fun!

Abs works better for impeller? Does it print the same?

@@DktheWelder its a special ABS and Polycarbonate blend , its way easier to print , almost no warping and annealing the print at 150 °C is the way to get a real solid and sturdy print, you could probably print a blade for milling wood , using this stuff

@@DktheWelder ABS might work as well, but I don't like printing ABS...

It’s expensive to keep buying the proper stuff the mig wire is a bit annoying how it’s curved but not too bad aye haha

I’m not sure . They are supposed to be high performance, maybe 4-5hp each they sound powerful haha

Ok I think you are right I will make an aluminium plate for the top need it more ridged

Nevermind I was interested and watched the whole series then i found link in description I bought the coupling $2!! thats so cheap can't wait to build my own inline 2 was just wondering what wall line count you used ?

I think I used 4 wall lines and printed it solid

Haha, good you picked up on it I get called Australian a lot!

Cool thanks I will check out your videos some time👍

Maybe setup in a boxer setup would be best I think it would help with vibration

He said he was going to water cool them . It will be fine

It was crazy the temperature was different on them after that short run

I would like to do the two into one exhaust but I’m sure I would have to recalculate the shape?

these are supposed to be performance motors that are 5.5hp but I don't believe that for starters the carb diameter is too small . also these have a ported piston , how do you port these motors?

when your are 100kg and only have 5.5 hp in a pocket bike you notice .25 hp I was racing boys that where only 50kg , those so called performance engine use to go slower than one without the gold head, the squish was around 2mm. you need to machine the top of the barrel in lathe to give a piston to head of 0.6mm then widen the exhaust port to just under 70 percent of the bore size, and then raise the exhaust port in a nice arch to I think 18mm from the top of the barrel, thats of the top of my head, its been 10 years,use a air die grinder it takes about 5 minutes, I need to check the 18mm part, it was around 175-180 exhaust duration, when you got it right it sounds like a chainsaw on methanol, cheers Brett

@@kermets that’s some great information there mate! I have welded a jacket on one cylinder for water cooling . Do I have to do all those mods together? How much power would that give also seems like I need bigger carb?

yes you need to do every step, and the 21mm carb,and exhaust... I cant find the distance from to of barrel to top of exhaust port, you would need to fit a degree wheel on and work out 175 degrees of exhaust, they are bit on a pain engine to keep going and wear out quicker with double the hp, a big 4 stroke maybe better like a 11hp honda copy, I did find a dyno run of one of my better builds i raced, drive.google.com/file/d/139c65Gt8dLjvcB6HR1AYDMioDff1WBnq/view?usp=sharing

Thanks it does sound cool , not much power unfortunately 👍

I got them off trademe a New Zealand site, but they would be on eBay I’m sure just a pocket bike motor

@@DktheWelder awesome. Thank you!!!

I just wanted them to run opposed so it would run smoother

@@DktheWelder ok, THK

👍

Yeah I actually had one of those cables but it wasn’t long enough. I will make a kit if enough people ask for it

Na but I sell a drawing for 3d printing it for like $2 search dkthewelder on CG trader and you should be able to find it