Simple TwoStroke Cylinder Porting Tutorial
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- เผยแพร่เมื่อ 6 พ.ค. 2018
- I made this video long ago, but forgot to upload it. This is a very simple tutorial. You should read about how the two stroke enigne works before you attempt this. This can easily ruin your eninge, but can also increase performance by alot. Just be careful and dont port to much at once. Do it slowly and you will learn as you go. If you have any questions be sure to leave them in the comment section.
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Oh man that was so nostalgic seeing an old Honda MT5 being worked on, had one myself and it taught me everything I know thanks to breaking down all over the place atleast twice a month xD
Seriously , info is good .
Music TOTALLY BLOWS !
I once had a go at porting my first 2 stroke. I read the book '2 STROKE STUFFING' by A Graham Bell from cover to cover many times first. I ended up with a peaky piece of junk, but I road it anyways 😄 I learned a valuable lesson.....Start small and take more off later!
Haha thats very relatable. I would say its on of the best books to read on this subject. You are also completely right. Start small :)
You are supposed to use a degree wheel to check the opening in terms of crankshaft degrees. You need a 90 degree hand piece for the transfer and boost port!
Awesome video man! And beautiful mt5:D
Thanks :D
Add bigger carb, and skim the top, as you decrease compression when porting the exhaust.
Don’t forget to Lube needlebearing, rings and cylinder when putting all together with some 2 strokeoil
Yes, I forgot to mention that :-)
DidrikNaper you could have mentioned jetting up may be necessary depending on how much you take out.
Here's a tip for you Didrik: never raise an exhaust port without also raising the transfers, as increasing the exh-lead only will cost you torque (hopefully made up for by the rev increase)! Besides, you will need a new exhaust sooner than when doing both.
And, on your bike it looks like the reeds are always 'connected' to the crankcase so no lowering required there.
Oh, do not chamfer the edges of the piston that way, bad habit - a minute rub with fine sandpaper is all that's needed so as to 'break' the edges.
I agree with you. I made this video long before I uploaded it. By raising the exhaust duration, I am losing torque and also getting a smaller and more concentrated powerband at higer revs. I normally like to keep my cylinders at a blowdown at around 30-35 when it comes to the transfers, but it depends on what type of ride and powerband I want. The piston thing is not needed as you say, and it will also result in a bit of lost torque by lightning the piston.
So not true!!
What about reversion, wouldn’t raising the exhaust port without raising the transfer decrease diversion?
Thanks for the great info!! I'm awaiting the arrival of a long block and have thought about porting the head. I've done machine work on automotive heads, thanks for the help. Killer video!!
Thank you and good luck on your project :-)
Didrik, Did the same on my yamaha rx 135, [ the larger bore version of the rs 125] though I had to make do with a hand drill, which prevented me from making indentations in angles; instead I had to make full 90 degree cuts. Works great, though I lost a little bit of low end torque, perhaps due to the loss of angles on the ports but the upper end is way better.
Though not shown in the video, I found that dipping the entire material which is being ported, whether the piston or the block in oil [ 2t] helped in catching the loose metal flakes.
I have done that 45 skirt bevel many times to reduces oil friction and push oil to the ring lands better.
You don't necessarily have to deck the cylinder if you raise the exhaust duration unless you baseplate for more transfer duration, or the deck height ion the cylinder is wrong in the first place.
Plus you can deck the head for more compression.
You actually lose volume when you add exhaust timing.
@@smokepeddler You are totally right Ryan. Did this on my performance engine. Worked extremely well. I also reworked the combustion chamber on the top. Used the information from A. Graham Bell in Two stroke performance tuning as the basis :-)
@@DidrikNa another great tip for cooling on a Reed valve cylinder is 360 degree intake timing.
You can do this by cutting an arc on the intake skirt of the piston so you have overlap flow with boost ports and skirt thru intake port.
Keep up the good work.
Nice
Sir, I need such a help. I want to ask about the port of such a cylinder, how can we increase the speed from its port. Please help me. Please tell me.
7 minute video just to NOT show the end result ?
bruh, i let that annoying af music running for nothing all throughout the video...
I can upload a video for you ;)
@@DidrikNa yes PLEASE
i felt kinda pranked after i heared the first revving example and was eagerly waiting for the resulting sounds but instead got that default music
@@DarkIzo I understand that :-) I will see what i can find. It wont be very comperable because I was using another ignition but you can search for any mt5 cycle express video to compare to mine 😉
Amen on hearing the results I was eager to hear it run and to my disappointment nothing but that crappy music.
@@DidrikNa wow i can't wait! (•_•)
by doing this u made the exhaust port to big probably losing power, if anything u want to aim the flush channel
's
better at the spark plug , getting to this angle u can pretty much forget with a dremel and accessory like that , adding compression via lowering the head, will lower the top rpm and there for lower the top speed. adding a bigger carb will also give it less fine droplets of fuel, and would only run good at wide open throttle.
Raise the compression, then you will feel more power, promise..
Raise it too much and the engine will ping.
Reworking the swish band
std head was pants.
@@ronito1271 you will FEEL the power...
@@Ni9kye the degree???
@@jensentidurmakan6404 follow the shape of the piston crown, the squish gap should be as close as can be without piston hitting head at high rpm. Remember the rod will stretch at high rpm. a gap of 0.7 mm should be good.
You will have to take a load of material off the head to do this work. Somthing in the order of 5mm. And have to shape the dome in the center.
You will find that the long bolt fixing the head to the frame will no longer line up! so you will also have to grind out the fixing hole in the frame to compensate.
If you have the time All of this work can be done by hand using a 12" x 12" 6mm plate glass for flatness and emery cloth and dremmel for the reshaping.
You sure you want the edges lager and use the dremel? 🤣 Top Engels man
do you have to change jetting after a porting ??
It really depends on your setup and how much you port. I would recommed tryinh different jets when tuning anyway, to see what works best for your setup
that's all? hmm good job, but.. i think you still knowing not to much about how to increase 2 stroke engine performance from porting and polishing, but what you did is alright, try touch or learn about how to change the transfer port, diameter, degree, angle, timing, flow, head cylinder, etc that is also increased significant power.. on my video was the result of our 115cc regular 2stroke engine (not special engine).. hear the engine respons..
the title says simple, not extreme performance porting
Hay I have a 100 cc Suzuki can u help me out.
what are the tools and where did you buy them >>?
Your MOST important tool is your brain. Get it filled with as much information about two stroke engines, then form your own opinion because everybody's idea is slightly different. Read the Jennings book and the Bell book for starters. All online somewhere.
If you don't have money for a grinder, just use some regular files. I did when I ported my DT175E cylinder. To reach the tight spots, just bend the file. Use a hot flame on the area you want to bend. Just use enough heat so that it won't snap. Practice on an old file first. I found an slight S-bend worked quite well. Make sure your file is sharp so that it cuts as fast as possible. Use your other hand to apply downward force on the file so that when you pull with you main hand, the cut is effective. Only cut one way, else you will dull your files. This takes a little longer BUT you won't need to remove a lot of material. I think I removed about 1.5 mm off the top of the exhaust port on my bike and there was a definite increase in the way the engine would deliver its power. My brother had a newer DT175 (1981 model) that was standard. We did a side by side drag race. I could run the engine speed higher in each gear and this allowed me to re-pass my brother's bike who had slowly pulled away from me. This may have been due to some loss of power or my engine was just older.
Don't omit the slight chamfer the piston rings need so that they do not get trapped. Some books do not explain this very well. The rings need a shallow or small angle to allow the cylinder side to gently push the ring back into the piston as it passes the top of the port. The size of the chamfer is determined by how far out the ring protrudes from the piston during the time the ports are open. If the chamfer is not done or is done wrong, you could be finding broken rings in your exhaust and no compression. Been there, done that.
Don't only port your engine. Use a slightly larger carburetor or get it bored out. Raise the compression ratio a bit. Most regular fuels can handle a little higher compression before knocking starts. If you try methanol, you can raise the CR quite a lot - and this means a lot more power but shorter engine life. Any change for more speed and power needs more fuel. Get ready to buy larger jets or whole jet sets if you are doing methanol.
No dyno sheets or anything to see the gains? I ain't subjecting my RG to this until some proof. The tutorial was fine, though
Tuukkis andhe's just doing the most basic port job that everyone recommends for beginners, it's 2 simple steps.. #1 raise exaust. #2 lower /expand width of intake ( never touch the top, just bottom and sides) trust me it does work, just a business card thick to feel the power but with more power comes more bang! along with wear,(obvious you will run leaner so jeting up Is recommend)PS ...the piston job is cool but not necessary.. will help with wear.. good luck✌️
yeah dont do this at all. dudes a dame troll
Wow i have the yamaha version of mt5, yamaha dt 50 mx. They were really popular back in the days
funny that when i was 16 the MT5 was a honda...
now the yamaha dt 50 x is really popular. At least in finland.
@@ruuvivaras6305 Nice, i hate yamaha for not making them anymore or any newer dt 50 really. In norway, every person i meet with mine, are shocked because they want a dt 50. The problem is that you can barely find ones in good condition for a decent price. Everyone be riding around with Rieju mrt 50s, and there is always a problem with them. Dt50s were very popular back when they were made tho.
@@lengaming1651 you can find a bunch of Yamaha DT's in Finland. I got one for 150€, but it was in really bad condition. It was rusty, the paint was bad and it didn't run. But I'm planning on making it a 70cc sport supermoto. I do really wish they made them nowadays, but I guess Riejus, betas and fantics are ok too. I have a Rieju MRX and it has so many problems, despite fixing it all the time.
@@ruuvivaras6305 Beta rr seems to be the best these days and they are still being produced. Easy to find parts, deadly performance when tuning it right and good quality over all.
alexc you dont have to dremel yuor cylinder ;i dit cut on the top of the piston the inled and exhaust 2mm ;if you head now l pistonring .mutch better piston gets lighter. try it whit puch maxi ;man it flys and try a thicker foot gasket..you just need a file
In Britain, MB5 was worst ever to do any work on. Honda put restrictions 'everywhere' to prevent tuning. The rest of Europe got a 6.5bhp version UK had something like 2.7bhp 30mph Even the exhaust needed cutting open to pull pieces out. I think it only had a12mm carb? Even fitting a cylinder kit didn't help much, they were horrible
yeah , rest of Europe exept denmark , we are stuck with 1.2 hp max and 30 kmh 😒 for 15 year old kids on a beginner license , from 18 years u can drive a "big moped" ie 45kmh , it does however require a car or motorcycle license 😂🤨😮
@@Luske74 I didn't know that. British MB5 may have been 1.7bhp not 2.7?( , long time ago, I forget stuff.) .30Km must be way more dangerous than 45km or are most speed limits that low in town? (24mph?) 'We' tuned Yamaha FS1E (Fizzy) to get 60mph+ way back in late 1970's (77,78,79) The Honda was horrible by comparison Suzuki was easiest, nylon spacer to prevent full throttle
You were doing it wrong, my mtx50 had same motor as a mt5. To make it fast you needed a 65cc big bore kit, reworked head, gianellie pipe, mtx80 manifold, h100 carb.fibre reeds. Would pull 70mph on the flat with ease.
@@Ni9kye I don't think you fully understood what I said.
It was possible to tune MT5 but it wasn't the easiest. Yamaha was the easiest fix followed by Suzuki then Kawasaki
On the Honda everything from the airbox entry to the exhaust tailpipe had restrictions.
@@peterjones6945 yeah your bang on it wasn’t easygoing I remember having to get a special rear sprocket as I ran out of gears. Some 35 years ago there were tons of 50s on the road. Yeah good ol day’s.✌️😃
What you also can do what i did was buy a 80cc mb engine and ported the crankcase to fit a 125cc😏
Have tried it :)
hi can u tell the model and year of ur bike
Honda mt5. 1992 I believe
Measure on a flat surface! Not some old messed up saw horse doh
AT&T
is this 50cc or what
Its a 70cc kit, but its only 66cc ;)
Look Up Honda MT5
I can't believe Honda sold a bike with he exhaust going under the tank!
The expansion Chamber is not that close to the fuel tank, the tailpipe is close to it right wereld the Seat begins, bit its not that dangerous. I have personally bever heard of an accident related to this and know a lot of people who own a mt5
It's pretty common for Motocross/Off-Road/Enduro bikes to have the exhaust like that, just have a look at Honda Motocross Bikes 1973-2014 th-cam.com/video/w00l3T8TU4s/w-d-xo.html
Ok , you dont belief.
When you put the piston in the vice...
There were some rubber pads on the vise, and it won't bend the piston if you don't overtighten it..
Så you dont measure squish clearance hmmmm?
Why would you measure the squish clearance if you don't lower the head or cylinder exactly?
Squish is very important on 2 strokes, always out from the factory
@@jepulis6529 Squish is one of the must important things you can meassure ;) to small squish and you engine will run to hot and stall and to big and you will lose POWER. My cylinder shall have a squish on 0,65 mm and i have a 70 ccm 47,6mm T6 Airsail Racing ( it is a semi-racing cylinder ) and the sport pro mk2 from stage6 shall have a squish on 0,60 mm
@@Mikkel028 yes, but he did not change the cylinder nor lower the head or the cylinder, assuming he used original thickness gaskets he doesn't need to measure the squish because it won't change. And it is a low-power engine so it would need a pretty big change to tighten the squish to detonation levels.
With the same size gasket he shouldn't need to adjust for squish clearence. However it's allways good to know what the squish band should be, a common rule is 1% of the stroke length is a good start.
Ever heard of a degree wheel?
Offcourse :-)
Not what's that?
@@DidrikNa nope
Ahh, Better low end power and idle... NOT!
Using aluminum spacers is a bad choice
Hope he balanced them
😱😱😱🤡
pauvre type
Hshaha is this the 2-stroke comedy channel?
Why the horrible music?
Pp
Why do people have to put music in there videos, seriously crap ! Why not just talk us through it?
When editing a video without music it can see very dry and boring, so maybe he was just trying to make it more entertaining for us. I agree it is distracting but I am sure he has learned.
Get a rsx100 engine init
Maybe change the title of your video instead of misleading over 200K people. This is an entertaining video, but not only is it not a tutorial, as the title claims, there is also misleading and bad information that others will use.
Saying "You should read about 2 strokes before you attempt this" does not make this acceptable.
the music mate??? seriously.....great video but the rubbish music??? Ruined it and I cant recommend your vid to anyone, sorry
Hey, thats no problem. I just put on some no copyrighted music. Infact I don't like it that much myself, but you can just use the mute button if it annoys you. Br Didrik :-)
Hajnd
P
Too difficult to understand
Bugger off
@@Roopak-Mohan lols ffs thats my phrase haha
Dude why put a new piston in a worn out cylinder, ever thank of taking it to a machinist have him bore it out and put an oversized piston, you put a new piston in a worn out cylinder hope you like to rebuild it in a couple of hundred miles.
Swapping new piston in an old block is common in 2stroke engine.... It is even recommended in certain manufacturer following their operating hours or mileage interval...
This was just and example. I was not going to use this setup, so I wasnt as thorough as I am usally :-)
@@AmirPomen It maybe common in your world but in the real world nobody in there right mind would even think of doing this type of well they been doing it! Really just trying to help you raise the bar I've been working on bikes since I was a sophomore in highschool I earned a lot of first time. awards from many big name company's I know big wop, I have a reputation, good one my customer's want the best that's the reason I have made a good deal of money by doing it right the
@@hank5655 dont get me wrong... Obviously the best method is toreplace everything with new and correctly gapped ring/piston clearance and such...
In this vid we cant even tell how bad or how good condition of the cylinder...
My earlier reply is in general if the cylinder is worn but still within tolerance as specced in service manual (no big scuff or deep scratch)...there is nothing wrong with just ring+piston replacement (after measuring piston ring gap and piston diameter)... It even stated in most factory workshop manual to inspect, clean or change piston+ring when needed on used cylinder block...
and i still apply similar concept on my race bike engine for every rebuild... Reusing cyl block but with new piston and rings...especially when the tight regs didnt allow us to run oversized piston over 0.5mm due to displacement limit....
If we do replace the piston,rings and new cyl. block on every engine rebuild, the cost and wastage factor is too high for us and not really justify-able for just probably negligble differences of power output or reliability...
Anyway.. im not trying to start an argument here... Im just sharing a bit of my point of view in certain engine application...and i still throw away (or resleeve) badly worn cyl block anyway...
Putting a piston in a flat faced vice is a no no ,pistons deform all to easily which leads to failure ,why would you teach someone to modify the cylinder when it's more expensive then shaving the ex port edge of the piston until desired opening then tune the barrel accordingly ,that's common sense to any tuner
Song ruined it.. great bike.
40 seconds into the video and you're already fumbling around with the ratchet trying to remove the tank.
Will see if the rest of the video shows any skill or just a guy making videos for likes
WRONG NEVER DO YOU PUT A CHAMFER ON THE PISTON EDGES. JUST THE HIGH STUFF!. THIS IS SO WRONG ON EVERY LEVEL
Nice
Nice