Rotory valves on a high performance 2 cycle engine are effective up until the centrifugal force starts to reverse the flow in the valve, throwing the mixture back at the carburetor. This was the experience of John Taprahanian when he built up a ( outboard) 4 cylinder Johnson PR-55 for racing. He eventually went to brass reed valves, and set a world record for the 66 cu" class.
wond if there is a way to form the rotary valve or shape the intake side of the "block" to drive( or create a negative pressure) the fuel mixture into the hole.. even better, a standoff injector just in front of the rotary valve (Renault did this in F1, when their wide angle block had resonance problems in the intake , as a result of high vibration, and electronic noise bugging the injector sequence.. perhaps combine a carb for low end throttle, and a standoff injector comes in only on the pipe..if one could get around the oiling problem..may clog the injector.. would make for a wacky fuel deliver system .... Never understood positives a rotary valve give's you.. what's the reason they were chosen in liue of reeds.. ?
The secret to starting ANY functional two stroke, pull it slowly two or three times letting it just bump over slowly, then pull it harder. You do this on a KX250 and it will start with a softer kick than you could have ever imagined. Once it has cycled those few first slow times, one uniform slow kick or pull will get it going. This works for any two stroke I have ever encountered, dirtbikes, chain saws, whatever, it works
Problem is it wasn't 100% functional :) the flywheel taper was damaged a little bit and it was moving every pull (recoil starter drives the flywheel), screwing up the timing. We adjusted timing several times but one pull later it had probably moved again. It starts first or 2nd pull now that that's fixed :)
Hi! Once in a week yes i agree...but try to drive a 2 stroke 50cc everyday and you will change your mind about the smell...try long drive and you will change your mind about the sound! I have now a 4 stroke scooter with a big bore and a few change and I go faster than any motorcycle or any thing with 2 wheels in town and between here in France because it is smaller and speed limit is 50 km/h so about 32 mph and there's radar everywhere so agility torque and a good eye are what makes the difference not horsepower!
@@shaunpc2512 🤩👍🏻👍🏿👍🏾👍🏽👍🏼👏🤝🖖🏼...a totally different world...I agree! Now that I think of it 2 stroke vs 4 stroke is a consideration of the past now!!! Have you tried any electric motorcycle or scooter? I tried a few and the last one I tried was a "50cc" whose speed is 50kmh or 32 mph but with an internet app it go 100kmh so 63 mph(there is an USB port to charge a phone but if you do a manipulation it double the speed but it work only once you have to do it every time you start the scooter so in case the police arrest you they can't proove it!) I try an e-bike with the same kind of modification but build in no app needed...wow it was fast and very nervous...it can burn out...and it wasn't that big...maybe kind of 400cc...the day they will built something who equal a 1000cc it will be crazy! There is e-bike who have the same acceleration than your CR or KX(I use to have a kx 80 an YZ 125 then 250! Long time ago)now but maybe not the same sound 😉 and you will need a lots of battery!
@Must B Nutz MOTORIZED adjective UK usually motorised uk /ˈməʊ.tər.aɪzd/ us /ˈmoʊ.t̬ə.raɪzd/ motorized adjective (WITH AN ENGINE) specially fitted with an engine or motor: a motorized wheelchair SPIN verb uk /spɪn/ us /spɪn/ present participle spinning, past tense spun, past participle UK also span spin verb (TURN) to (cause to) turn around and around, especially fast: The earth spins on its axis. thing noun (OBJECT) A1 [ C ] used to refer in an approximate way to an object or to avoid naming it: What's that thing over there?
I remember hearing of a very old farmer here in North Wales flogging a prone horse. He flogged it all day to make it get up but it turns out it was an old log! I'm sure there's some advice in here for you but I can't remember what it is? Oh! I remember now! You don't need the ear defenders!
Yeah I gave up on dirt bike riding when most manufacturers went to shitty thumpers. Long live 2 strokes! Glad to see some manufacturers are bringing them back. 4 strokes just aren't the same, & in my opinion are only good for road/trail & long distance cruising. For tight, technical, jumping & pretty much any hard riding 2 strokes are king. Plus their power delivery is way more fun.
When your goal is performance, you have to be persistent in working out the bugs n gremlins that plague the ICE world, sometimes its something set wrong, most times its learning the machines order of prerequisites for cold start- cold run- warm run- op temp run tunes you have to get fuel oil mix to line the cylinders and seal the rings, that wets the plugs and fuel fouling can make them go bad for good. Cold temp spark plugs don’t like high cylinder temps high temp plugs make it harder to start a cold engine (cheating with a pair of heat guns and an electric motor belt starter to get it spinning, fully lubricated, and hot. (Compression is friction snd makes heat which expands metal and the parts grow to their intended size) How much output?
Supposed to pull slowly 3-4 times at first to pump gas into the engine then fully pull the starter or their might be a problem with your jetting and air system in the carb.
Yup that's when it's time to fab up a electric starter. I would of went in the house after 30 pulls sat on my sofa and cracked a beer saying 🖕🏾🖕🏾🖕🏾 to that snowmobile 😂😂😂
Some serious energy was needed to get it running, pulling 900cc around and around. Those exhaust pipes look magnificent. Nice work! Those copper pipes are for keeping the butt warm?
He made them himself, I think the pipes were about half the work put into the whole machine. I guess a warm butt is an added benefit but there's a hole in the chassis underneath the radiator there so it gets cooled by snow while riding.
The flywheel taper was a bit damaged so timing kept moving on every pull, we adjusted it a bunch of times while trying to get it started because we thought we probably just didn't set it up correctly. It starts on first or second pull every time now after fixing that :)
That's gotta make a load of power my buddy's fan cooled 440 makes 90+ hp.. please tell me what this Frankenstein is supposed to make this thing is wild
that's a lot of motor to start by hand. Electric starters are getting small and powerful. Perhaps that's what you need? I love 2 strokes. May they NEVER die. so, I am guessing close to 200hp+?
People hand start worse than this :) but a starter motor probably wouldn't have helped this day, it was a timing problem. Now after fixing that it starts in 2 pulls usually, a couple more if he just rejetted and the float bowls are empty. He hasn't dynoed it yet but hopefully later this summer. I think he would be disappointed if it has less than 200 :)
@@maxpower700 Thanks for the reply, actually I have built many race engines, two stroke and 4 stroke, plus many high HP Chevy small blocks, guess I must have been lucky , never en counted any start up issues, maybe one one I will lol.
I agree with colin. 132 tries, never once seen a plug pulled to check for spark. I've worked on everything (pretty much), and i have in fact had some stubborn, but i wouldn't pull 132 times without checking SOMETHING.
+Alexander Jäderblom He started almost 2 years ago ago I think, can't remember exactly when. It was first supposed to be done last winter, then last summer, but now it's finally getting close :)
+David evans I'll leave that up to him, I'm not sure if he has any videos of the build process but I know he has lots of pictures. But we'll do a walk around probably in the next video and get into a bit more details.
@@audreymeschkuleit3466 I can't take credit for building them, this is my friends sled and he built them himself, I just calculated them. They are tig welded.
This engine was already built but in pieces when he got it, the crank was perfect though and didn't need any work. On this particular engine it's a full crank made out of 2 cranks and the center webs of a 3rd one, but there's also people that built engines like this with 2 separate cranks with a coupler of some sort in between. I'll post the build process of my own 4 cylinder crank when I get to that stage, probably later this summer.
Day 40, pull 5033 I'm exhausted but enlightened, found myself starter spray. Will come back later for more journal entries.
Lol
eamh2002 day 200 about 4,486,397 pull and it started
@@ridertvgaming1237 How is it going?
I had the same problem. Forgot to turn the key..amazing job
Rotory valves on a high performance 2 cycle engine are effective up until the centrifugal force starts to reverse the flow in the valve, throwing the mixture back at the carburetor. This was the experience of John Taprahanian when he built up a ( outboard) 4 cylinder Johnson PR-55 for racing. He eventually went to brass reed valves, and set a world record for the 66 cu" class.
wond if there is a way to form the rotary valve or shape the intake side of the "block" to drive( or create a negative pressure) the fuel mixture into the hole.. even better, a standoff injector just in front of the rotary valve (Renault did this in F1, when their wide angle block had resonance problems in the intake , as a result of high vibration, and electronic noise bugging the injector sequence..
perhaps combine a carb for low end throttle, and a standoff injector comes in only on the pipe..if one could get around the oiling problem..may clog the injector.. would make for a wacky fuel deliver system ....
Never understood positives a rotary valve give's you.. what's the reason they were chosen in liue of reeds.. ?
Stratification people!
It's still easier to start than a ryobi string trimmer...
Ha
Ain't that the f*+-* truth lol
Most reliable rotary i've ever seen. Jokes aside, that's one very impressive feat of engineering.
That is by far, the best recoil starter I’ve ever seen on a Rotax.
you broke into the engine before it even started
The anger in that engine gives me the chills. Sounds fantastic.
The secret to starting ANY functional two stroke, pull it slowly two or three times letting it just bump over slowly, then pull it harder. You do this on a KX250 and it will start with a softer kick than you could have ever imagined. Once it has cycled those few first slow times, one uniform slow kick or pull will get it going. This works for any two stroke I have ever encountered, dirtbikes, chain saws, whatever, it works
Problem is it wasn't 100% functional :) the flywheel taper was damaged a little bit and it was moving every pull (recoil starter drives the flywheel), screwing up the timing. We adjusted timing several times but one pull later it had probably moved again.
It starts first or 2nd pull now that that's fixed :)
Somthing to be said for electric start
@Simon Roscoe flywheel was at the wrong point on the crank and was firing too early which is why it only ran at high rpms, that's my guess
and this is why the electric starter was invented :))))))))))
It was a lot easier to start when the ignition problems were solved ;) but yeah an electric starter probably wouldn't hurt. He's working on it.
@steelmesh heck yeah they do, fuel injection is much more efficient and an overall way better system
His helper must have been exhausted from pulling, he held up rear but no drive belt on the clutches....lol
They both had aches the day after ;) my excuse was I had to hold the camera :)
Just imagine if a polar bear is chasing you...
Kukut lek
Franco Barone eklkkkk rekkkk rekkk rekkkkkkkkkk 😂😂
How do you stay in shape during the winter? start this thing!
Time for a starter motor !
Wow 4 cyl custom 2stroke engine insane build!
That sounds truly amazing, I love the sound and smell of a 2 stroke 😃
Hi! Once in a week yes i agree...but try to drive a 2 stroke 50cc everyday and you will change your mind about the smell...try long drive and you will change your mind about the sound! I have now a 4 stroke scooter with a big bore and a few change and I go faster than any motorcycle or any thing with 2 wheels in town and between here in France because it is smaller and speed limit is 50 km/h so about 32 mph and there's radar everywhere so agility torque and a good eye are what makes the difference not horsepower!
logan leborgne that I totally agree with but where a track is concerned, give me my CR500 or KX500 over a 4 stroke any day
@@shaunpc2512 🤩👍🏻👍🏿👍🏾👍🏽👍🏼👏🤝🖖🏼...a totally different world...I agree! Now that I think of it 2 stroke vs 4 stroke is a consideration of the past now!!! Have you tried any electric motorcycle or scooter? I tried a few and the last one I tried was a "50cc" whose speed is 50kmh or 32 mph but with an internet app it go 100kmh so 63 mph(there is an USB port to charge a phone but if you do a manipulation it double the speed but it work only once you have to do it every time you start the scooter so in case the police arrest you they can't proove it!) I try an e-bike with the same kind of modification but build in no app needed...wow it was fast and very nervous...it can burn out...and it wasn't that big...maybe kind of 400cc...the day they will built something who equal a 1000cc it will be crazy! There is e-bike who have the same acceleration than your CR or KX(I use to have a kx 80 an YZ 125 then 250! Long time ago)now but maybe not the same sound 😉 and you will need a lots of battery!
Got one of those motors in the shed also, it was made from two 462's . I think the crank is broke on it . Cool to see one run again.
Very cool! This one is made from 2 454s.
That recoil lived its entire life in 1 start 😅
You are to be commended for your wonderful contribution to the two stroke cause.
Sounds like they all fire at the same time.
I would of put a motorized spinny thing on the crank
Or he could of just got a power drill and started it on the crank pulley. Also heating up the engine would of really helped.
@@benchasinghorizons9428 thats what i said
@@ACplanet no you invented a spinny thing.
@@benchasinghorizons9428 and then i invented motorized
@Must B Nutz
MOTORIZED
adjective
UK usually motorised uk /ˈməʊ.tər.aɪzd/ us /ˈmoʊ.t̬ə.raɪzd/
motorized adjective (WITH AN ENGINE)
specially fitted with an engine or motor:
a motorized wheelchair
SPIN
verb
uk /spɪn/ us /spɪn/ present participle spinning, past tense spun, past participle UK also span
spin verb (TURN)
to (cause to) turn around and around, especially fast:
The earth spins on its axis.
thing
noun (OBJECT)
A1 [ C ] used to refer in an approximate way to an object or to avoid naming it:
What's that thing over there?
I have a 45-70 that would fix all those starting problems
This is how my weed wacker starts lol
When I was doing that we always opened the throttle and sprayed wd 40 in the carb. It will make it fire and it will lubricant
Now that's a monster to be pull started.
I remember hearing of a very old farmer here in North Wales flogging a prone horse. He flogged it all day to make it get up but it turns out it was an old log! I'm sure there's some advice in here for you but I can't remember what it is? Oh! I remember now! You don't need the ear defenders!
That's a machine!
It is! I'm a bit jealous really now that's it's finally nearing completion... But not feeling too bad about not having to build 4 pipes for it ;)
Congratulations!! all the effort and dedication was worth it! Now enjoy it!
Any tips on making the cones have a radius bend in the flat sections?
Nothing like the sound of a 4cyl 2t
Sound reminds me of the old TZ 750 sidecars.
This particular one has 180 degree timing so it kind of sounds like a 4 cylinder boxer. Cylinders 1 and 3, and 2 and 4 fire at the same time.
Yeah the TZ750 had a 180 crank with 1 + 4 and 2 + 3 firing at 180 of each other.
Sounds nice.
Those were the days!
Yeah I gave up on dirt bike riding when most manufacturers went to shitty thumpers. Long live 2 strokes! Glad to see some manufacturers are bringing them back. 4 strokes just aren't the same, & in my opinion are only good for road/trail & long distance cruising. For tight, technical, jumping & pretty much any hard riding 2 strokes are king. Plus their power delivery is way more fun.
why did you not pull Spark Plugs to to see if you had good Spark or weak spark?
oh my god this is the coolest thing ever...what a beast
When your goal is performance, you have to be persistent in working out the bugs n gremlins that plague the ICE world, sometimes its something set wrong, most times its learning the machines order of prerequisites for cold start- cold run- warm run- op temp run tunes you have to get fuel oil mix to line the cylinders and seal the rings, that wets the plugs and fuel fouling can make them go bad for good. Cold temp spark plugs don’t like high cylinder temps high temp plugs make it harder to start a cold engine (cheating with a pair of heat guns and an electric motor belt starter to get it spinning, fully lubricated, and hot. (Compression is friction snd makes heat which expands metal and the parts grow to their intended size)
How much output?
Supposed to pull slowly 3-4 times at first to pump gas into the engine then fully pull the starter or their might be a problem with your jetting and air system in the carb.
Yup that's when it's time to fab up a electric starter. I would of went in the house after 30 pulls sat on my sofa and cracked a beer saying 🖕🏾🖕🏾🖕🏾 to that snowmobile 😂😂😂
So 132 pulls later and it starts? Love you TH-cam recommendations :P
Repilesko
Will be a beast to ride, soooo much power!
Have you considered a starter motor?..great job guys you made it in the end..Allan Millyard will be proud of you!
Nice workout. And for the legs I recommend a SR 500 😉
Some serious energy was needed to get it running, pulling 900cc around and around.
Those exhaust pipes look magnificent. Nice work! Those copper pipes are for keeping the butt warm?
He made them himself, I think the pipes were about half the work put into the whole machine. I guess a warm butt is an added benefit but there's a hole in the chassis underneath the radiator there so it gets cooled by snow while riding.
gosh damn thats my dream engine! but I would fit it in a drag car, thanks for sharing such an amazing build.
Nothing like that sound its got go dangerously fast written all over it! Atb Russ.
guts and determination there.
How do you link all the small 2 stroke engines together?
They are 2 2-cylinder engines. The 4 cylinder crank has an extra "center piece" out of a 3rd crank between cylinder 2 and 3.
1 woord. Geweldig !
Dankje!
So is that 2 444 motors mated together?
That is awesome 😍 but an elec start is a must lol did you work out why it took so much to fire up?
The flywheel taper was a bit damaged so timing kept moving on every pull, we adjusted it a bunch of times while trying to get it started because we thought we probably just didn't set it up correctly. It starts on first or second pull every time now after fixing that :)
@@Hollaendaren that's fantastic 😀 I have been enjoying watching you builds they are very impressive 👍 Cheers Mark
That's gotta make a load of power my buddy's fan cooled 440 makes 90+ hp.. please tell me what this Frankenstein is supposed to make this thing is wild
I would have tried using a drill on the crank pulley after the 20th pull and consider adding an electric starter.
These people have it easy. I ride a KTM
That is funny mate
Made my hands hurt watching, blisters and all.
Agonising to watch... but quite beautiful, ultimately. 😆
What was wrong with the fly wheel ?
MAN this sounds nuts
that's a lot of motor to start by hand. Electric starters are getting small and powerful. Perhaps that's what you need? I love 2 strokes. May they NEVER die. so, I am guessing close to 200hp+?
People hand start worse than this :) but a starter motor probably wouldn't have helped this day, it was a timing problem. Now after fixing that it starts in 2 pulls usually, a couple more if he just rejetted and the float bowls are empty.
He hasn't dynoed it yet but hopefully later this summer. I think he would be disappointed if it has less than 200 :)
It's actually a new bow flex machine for car guys
I placed a gas primer to the carburetors on my 1997 V-MAX 4 , 800CC Yamaha and starts in about 3 pulls in very cold weather.
It turned out to be a problem with the flywheel. It usually starts on first or second pull now (with choke).
Are those custom motors or just some motors you threw together
A che serve trubulare così se parte parte subito magari c'è qualche problema
Are you running waste spark? And are you running a battery?
I am pretty sure no waste spark, 2 triggers and crank is at 180 degrees. And yes he's running a battery.
Why was it starting so hard? Looks like it has 4 individual coils. Is it running an ignitech p4?
Why do snow mobiles not have electric start?
Is that a parallel twin coupled with another parallel twin? Getting 4 power at every single rotation!
Correct :) this one is timed at 180 degrees so cylinder 1 and 3 fire at the same time, and 2 and 4.
Wow so Two power per 180 crankangle right so its similar to parallel twin with double displacement for each!
Electric Starter would be nice ! :-) Damn your arms and shoulders were certainly well tested there !!!
Which will occur first:
A. Engine starting
or
B.Release of Half-Life 3
C. Them dying
Obviously, something is wrong why waist your time pulling it for so long ?check and recheck ?
Never had an old cranky sled? Never had a rebuilt tuned engine in a project car? :D
@@maxpower700 Thanks for the reply, actually I have built many race engines, two stroke and 4 stroke, plus many high HP Chevy small blocks, guess I must have been lucky , never en counted any start up issues, maybe one one I will lol.
I agree with colin. 132 tries, never once seen a plug pulled to check for spark. I've worked on everything (pretty much), and i have in fact had some stubborn, but i wouldn't pull 132 times without checking SOMETHING.
@@twisterzman jumpcuts suggest you dont see everything. And given their history with this stuff, im sure they check everything :D
@@Colinpowderfinger id consider none, maybe one out of all, lucky, yes LOL. But lets not say it out loud and jinx a good record haha
You guys are building monsters now, a bit different than his old sled. When did he start this build? :)
+Alexander Jäderblom He started almost 2 years ago ago I think, can't remember exactly when. It was first supposed to be done last winter, then last summer, but now it's finally getting close :)
The exhaust is more scarier than the sound xD
Why again did we not put an electric starter on it?????
Are you doing a complete vid on how they built the engine ,pipes,chassis, ect?
+David evans I'll leave that up to him, I'm not sure if he has any videos of the build process but I know he has lots of pictures. But we'll do a walk around probably in the next video and get into a bit more details.
Thanks love your single 👍keep it up great vids!
Thanks! :)
Nice Job did you Build design the Pipes from MOTA Program?
The pipes were designed with Engmod2T.
@@Hollaendaren Thankyou .They look well Made. Do you gas weld or T.I.G. Them? I also fiddle with Snowmobile in my Small cold Garage.
@@audreymeschkuleit3466 I can't take credit for building them, this is my friends sled and he built them himself, I just calculated them. They are tig welded.
Missing ether spark or gas. It seems to have compression. How can something as simple as a two stroke not start.
Hello friend, first the flakes of slab I'll wait will not work and you have to put more gas in low
All that high compression and it won't pull fuel?Primer pumps needed.
Reminds me off the old Cats from late 60s
Why there is not a better starter?
Why a 4 cylinder with a pull start??
Needs to switch to high speed recoil rope! That thing WILL melt snow when it's dialed up right I'm thinking...
Is that a snow Machine?
I think after 30 pulls theres something not quiet right!
Did they set the choke? lol
Any video of crankshaft?
This engine was already built but in pieces when he got it, the crank was perfect though and didn't need any work. On this particular engine it's a full crank made out of 2 cranks and the center webs of a 3rd one, but there's also people that built engines like this with 2 separate cranks with a coupler of some sort in between.
I'll post the build process of my own 4 cylinder crank when I get to that stage, probably later this summer.
Rig up a starter on the side
It sounds like maybe timing is slow
Man that sounds intimidating twist the wick !!!!!!!!!!!!
No matter how many beverages are consume, you should always put more gas in the carbinators.
Friendly reminder to prime your fuel systems
Start fluid and a drill with a socket to turn over
Why is he lifting the back end, theres no belt lol.
Maybe so the gaz can flow easier to the engine idk
What is it two 470 Rotax engines ?
Almost, it's 2 454 engines.
Super cool , I had an old formula plus 583 rotax non rave that thing was absolutely bulletproof .
Maybe decompression heads??
Looks cool, and I want you got some good tunes on
Lol, maybe it just needed some "start you bastard"!🤣
Ye mate
that thing is awesome.
They say 100+ is a charm
Did you have the fuel on ? Just kidding looks sweet
where are you guys out of? roy in idaho
We're in northern Sweden.
Is that a pull start
we want to see more!
I see they took the belt off so then can rev it up
2:13 era só colocar gasolina no buraco da vela nos 4 pistões que pegaria na primeira puxada
At least 300 horsepower right?
No ;) 300 HP from 900cc on pump gas is a bit much to ask. But it should have 200+. We're hopefully dynoing it later this year.