The most IMPORTANT 2 stroke porting rule I know... and why I STILL HATE aftermarket cylinders...

[@bermbuster6]

You have cleared up so many unanswered questions in a lifetime of wondering the basic rules of porting, raising and lowering transfer ports. Thank you very much for your honesty and information.

[@GreenlawMotorSports]

I wish you would start making videos again as you have such a great wealth of knowledge and I know it takes a lot of time

[@gasaxecustomsaws]

Thank you! I've watched countless hours on 2 strokes, not once have I seen this. Thank you, again...

[@treewisemenllc7281]

This is one of the most helpful bits I've heard/learned about an engine in a long, long time. Thank you for this.

[@brendanhayes2752]

I’m not a professional chainsaw guy but I loved the cut away. That really helped.

[@videoaustralia]

Im doing things with saws I never thought I would do because of this channel, you're an inspiration mate

[@juledoren]

I just start cutting exhaust ports out😂

[@StihlRunnin]

@@juledorenthink that’s where it starts. Didn’t last long hogging on mufflers myself before I decided grinding on the steel might help too.

[@onemantwohands5224]

Hey mate , checking in from brissie 🙌

[@billylee2312]

Probably the best video I’ve watched on porting. I feel comfortable giving it a shot now.

[@timothymilam732]

Excellent bit of information on that, and your correct on no one sharing information with anyone. I found that out years ago with the two stroke dirt bike engine builders back in the 70's and 80's. You would of thought you were asking for the secrets to understanding women, or how to convert lead to gold or something serious like either of those. So finding someone who isn't insecure about himself or his abilities to be above average in his trade craft is not the norm for such things as engine builders of any kind, especially preformance builders.

[@PolarisRider06]

Wouldnt this depend a lot on transfer port timing? If the transfer ports are opening before the ring gets below the top of the exhaust port that would allow the expanding exhaust gasses to push backwards into the case potentially igniting all of that as well as actually stalling the intake pulse if the intake port was on its last degree or 2 of being open. But if the transfer ports aren't open yet the expanding exhaust gases are still pushing only on the piston, creating power and the case volume is decreasing, which also stalls the intake pulse but its not screwing with the direction of air flow in the transfer ports, they are basically dead air. So the exhaust opening (ring below top of port) only after the intake is fully closed (skirt below port) is important because then case pressure is building to prevent reverse flow of exhaust gases when the transfer port begins to open (ring below top of port) which i would assume you would want to happen just after the exhaust cracks open so that the exhaust is starting to escape through the exhaust port and there is more pressure in the case that will force the intake charge through the transfer ports with more speed and expell the exhaust gasses faster But then theres the intake shit that needs to be taken into account... fuck. It's been 20 years since I've actually thought about 2 stroke port timing and I used to have the concept down pretty good and now I'm playing mental gymnastics once again trying to remember the theories on how it all works. Plus, I keep thinking about things that would apply with reed valve cases when there is an actual valve preventing backflow if the transfer ports are open before the exhaust is open... I wonder if I still have all of my notes on port timing theory, exhaust scavenging and expansion chambers, and all of the other shit I made copies of and printed out back then... Why the hell do I do this to myself...

[@junkyardboost8372]

The exhaust port always opens well before the transfers. This is called blowdown.

[@matthewziegler9756]

Thank you for that! As a newbie at porting explains alot. Appreciated much!

[@AndyH-13]

You explain things really well, appreciated. Liked, subscribed and left a comment.

[@edwinburns4785]

Thanks John....New to this porting hobby and this is the first I heard of this. Makes absolute sense. Off to the shop to check a 394 I have apart and waiting for parts. Thanks again.

[@FYMM69]

Truly appreciate the info. Info I would’ve never thought of after 45yrs of messing with 2 strokes !! Thank you

[@waywardshed9721]

Those big bore kits are all problematic, good tips man thanks for sharing. Keen to see this running

[@mbmcclure3579]

Thank you for sharing. Just found your channel today and subbed. I’m wanting to learn all I can and for somebody just starting this is very much appreciated information.

[@brub5174]

Lowering intake for more torque. Highering exhaust for more top end. Damn dude. Thanks. You got a sub. Will try to port my own echo 3510. Not sure if I want it snappy or high end. Or a little of both lol.

[@herbertsmith2640]

Thanks for the information. I'm new to 2 strokes. Really appreciate it

[@calebthacker2162]

Wow I’ve never heard this…appreciate the share of knowledge 💯

[@charleimcdonald896]

Good stuff

[@Shiddyvet]

This is an awesome video. I still don’t understand a lot but I’m learning!

[@2Cheap4society]

Great video, very good point you are pointing out! For those who did not catch the facetious statement about taking out the top ring and trying compression check, basically It is because the combustion chamber is not sealed. You have a few degrees of crank rotation before it seals. If it's sealed earlier in the stroke it would give you higher compression. Like he said it will run but the compression would be lower than if the chamber was sealed.

[@doingitwronggarage9651]

That was a good tip. Thank you. Subscribed now. Always interesting to hear and see how you "over there" think about things differently. Like focusing on exhaust port opening and transfer port opening in the unrelated degrees after TDC in stead of total open duration that is based on degrees from bottom dead center.

[@mikeaustin1788]

What about modifying piston skirt to open intake earlier?

[@matthewknight5641]

Man i know you are super busy but id absolutely love to be able to learn even9re from you. I watch alot of your stuff and have just gotten into porting saws. I love my new hobby and i appreciate what you do

[@LocPH.]

Not sure if I completely understand, but how does a ring that's too low while the intake is opening lead to "short circuiting" if the transfer ports are closed? I understand that the earlier you can get the ring to seal, the more compression you have, but what has that to do with the intake?

[@1212zorz]

Glad I'm not crazy for having the same thought. Intake and exhaust being open simultaneously while transfers are closed would not lead to free porting. Unless I'm missing something major but spinning around my cutaway I don't see a problem.

[@adamspencer3620]

That cleared up a lot of questions I’ve always had about the intake charge Without proper ring seal you have low negative pressure

[@TTisleofmanTt]

Excellent vid.this is exactly how I work out what I can do to a saw.

[@matthewnorris203]

Interesting. Porting seems like such an art. I like rules of thumb like this..

[@Anthony071177]

Very good tip I’ve never heard any other channel mention. Thanks.

[@jonathanhalverson2380]

Thank you for the heads up John, I've been building and working on saws since I was a kid and I'm just now starting to mess around with porting and any other ways to gain extra power out of most of my saws or when ever I get new power heads. A lot of the stuff that I have learned is either from your channel or the IronHorse and I have to say you both have a really good knowledge on the do's and don'ts when it comes to hopping stuff up. So once again thank you very much for the quick awesome trick on how to tell if your saws going to have good power out of the box.Also at least that was an aftermarket head, but still don't blame you for being pissed off on wasting your time when you could have prevented it like you said. P.S. I like the video for ya👍

[@Macgyver-ranch]

Thanks John. Now I will have to check the cheapo big bore I pulled off of the 066 because of an odd miss. The intake was way too low out of the box.

[@walkerscountrylife]

Never heard anyone else talking about this and it makes total sense. Thanks for sharing, keep up the good work, appreciate all you do buddy.

[@RichFife]

Game changer for guys. Great Information!!! This is what helps everyone in this community. Thank You. John, what about a husky piston in that cylinder... it should have a higher top ring.

[@tylerheard1279]

Hell yeah! Makes perfect sense, just never thought about it that way.

[@williamgrissom1995]

This is a great help to me. I bought 2 G111 saws and I considered cleaning up the ports. Roughish on the intake and polishing the exahaust. But I won't unless the saw is too disappointing. One bit of advice I got to make them run like the 200t was a gasket delete and to port the muffler. I'm not looking to make it a mini race saw. I just want it to cut as well as my 200t I use to have did. The 200t was brand new when I bought it and just stock.

[@geralddavis9236]

Good to see you back in action i wondering why I hadn't seen any of your videos

[@hansondan06]

The amount of knowledge I’ve gained from this channel is insane. Thank you

[@flakey7832]

we don't have this very cool saw modding thing here, but we do have 2 strokes so this can very well be applied to scooters as well, great videos

[@chrisjacobs2182]

Thanks for sharing your knowledge to help us all out thank you!!

[@mirceastaicu4131]

If only everyone would be as kind as you, and share your hard earn knowledge, we wouldn't be wasting thousands (if not more) of man hours. Sadly this happens in most industries, entire business models are created on asymmetric information. Thank you!

[@kowski9477]

Great video man! I can absolutely understand what your explaining here and yes it makes total sense. Good job keep sharing your knowledge, thanks!

[@cheeseymccheese7249]

So at 8:00 specifically. Where and what would you grind out. Would you focus 75% on dropping the intake and then 25% on the exhaust or 50% intake 50% exhaust or 25% intake and 75% exhaust. Thanks!!, Hope you see this comment, its been over 2 years since you put this video out

[@chrisseger6870]

I learn something new every day, man. Makes me wonder if the first saw I ported (which I will never show anyone the cylinder because it's horrifying) had that issue on top of what I did to it...🤔

[@Kirks_Custom_Chainsaws]

thank you John! as always.... you are a wealth of knowledge as well as a pleasure to watch. you're a 2 stroke magician man!!! Keep up the great work & keep the videos coming!👍👍👍

[@rickfuerst]

I just ran across this video. I just happened to have a 046 & and a 064. I plan on some engine work on the 064. Thanks for the info. Great content! You rock!

[@nip917]

I learned so much from your limb reaper 200T, I was able to do my neighbors for him and he loves it. Won't even touch his stock ones anymore. You passed on the knowledge and I'm thankful.

[@martygoodell9287]

Just came across your site. Impressed in the few minutes! Thanks

[@BigJohn_Browning]

Thanks brother...I'm always learning from you...keeping it rowdy.

[@timcline2799]

Excellent site. Glad I found it. Thank you!

[@timstone721]

Great video and knowledge, I really appreciate this advice, thanks

[@chriseller757]

First I've heard of it so thank you sir

[@lachlanhawkins4236]

Just compared a genuine to aftermarket and your spot on

[@beekone28]

that is a very simple check no one ever told me on any channel! thanks a lot!

[@kraftzion]

I watch a lot of saw modding channels and have never seen this. Instant new subscriber.

[@helloallyouppl]

Got this on my main feed, looking forward to seeing more content

[@Ecksterphono]

Don't feel bad. I've jumped the gun once to on not checking the fitment and kicked myself. We all have our blond moments when not checking aftermarket components beforehand no matter how experienced. But at least we catch it before major embarrassment occurs if we would have assembled and ran it. At least you got on top of it. Great learning video for the novice and thanks for the heads-up.

[@bmp0149]

Really appreciate passing on of info. But I dont get this one. What are we saying the problem is with the inlet opening before the ring closes the exhaust ? Is the probIem during compression stroke - seems to be what's suggested - but I cant see any pressurised mix reaching the crankcase let alone the inlet. Or is the problem on the exhaust stroke where there might be a pressure pulse generated in the exhaust as the ring crosses the exhaust port ....could generate a pulse into crankcase and inlet port maybe? Be great to get a reply !

[@cgriebel1]

I'm also interested as to why it screws up performance. It would have been great had he delved into the issue/problem that is created by this mis-match. Perhaps he'll see your post....

[@cgriebel1]

Perhaps the lack of seal for that portion of rotation negatively affects the quality of the vacuum, and the volume of intake charge being dragged down into the crankcase?? Guessing here...

[@jasonsayre8102]

Great info my man, we def appreciate the knowledge you share!

[@joepilkington1646]

This has just made things so much easier for me

[@doglegjake6788]

Thanks for sharing another cool video !

[@sporranheid]

Don't get mad, get even 😜 A great gift! Thank you.

[@kylecromp319]

So how are you makin up the stroke difference? The 064 crank is wider than the 460.

[@lumbearjack3722]

Never heard this before. I’m interested if that’s why a few saws I’ve done don’t run as well as the others

[@pauldharmer]

First time here, have 2 031av saws to rebuild, guess I'll be binge watching for a while,

[@shaner67]

Thanks John for the really important tip. Please don't even worry about the haters, just jealous of your skills and knowledge. BTW, would like to purchase one of the awesome 462 builds. Please message me on how I can get a hold of you.. all the best my friend 11:24

[@justinweaver8787]

Very cool information thank u 4 sharing!!!

[@allenbrown7820]

Always learn something watching your videos.Keep up the good work.

[@ronsilva516]

Good advice 👍

[@ppesquire]

Great info. Thanks for sharing . It makes so much sense, now that you pointed it out.

[@yungsmile7546]

That's gold.👍👍

[@stevkolasab7269]

But why? The crank case is closed already the transfers are closed so it is not affecting this i dont understand it can you explain it to me please? Thank you

[@trentbikes]

I'm wondering the same

[@ocsplc]

John were with you 100% buddy. Thanks

[@codyabbott4791]

Is scavenging not a factor without an expansion chamber? Because with dirtbikes and snowmobiles they say having a slight overlap allows the exhaust gas exiting the cylinder pull a denser fuel/air charge into the crank case making more power.

[@customsaws]

Thanks for sharing. 👍

[@ronsilva516]

That was very helpful I kid you not that was very very insightful thank you 🤣👍👍👍👍

[@1crazypj]

That is something that was talked about in the 70's, 'free port' where intake and exhaust can be 'open' at the same time. Even though I've never done chainsaw motors, 'everyone' tuning two strokes should know about it and check. In early 2000's when 'pocket bikes' were everywhere, tuning them was a lot of fun , guess they were similar to chainsaw motors? Something else people don't realise, every time you raise exhaust you lower compression slightly which loses torque. Majority of two stroke run a corrected compression around 6~7:1, I always laughed when people started saying they were running 'race gas' and 14:1 (or more)

[@Justme001..]

Thank you for this info!! 🙏

[@user-cw2gs4yk2n]

For me both the rings are above the exhaust roof when it starts to let air and fuel in,is that even better?

[@scottwilson4396]

Thank you for sharing that info John 🫶🏿

[@mechanech]

Thanx John!!!

[@DesertSawyer]

So can you add base gaskets to lower the upper exhaust port? I know compression would be less however, is the addition a benefit?

[@latinodeathjazz]

Well that explains a great deal. Thanks for sharing that.

[@Hboysoutdoors]

Thank you first time hearing that

[@Kiltedwoodsmith]

Mr John can you port a ryobi saw and raise the CC's ?

[@leifmorris5114]

Great video

[@grabo454]

Thank you so much for sharing!

[@mm88swrt]

Well I guess I now have to go look at my saws lol. Never heard of this rule and I've been watching a ton of builders

[@JimmyOToole-bu5qk]

cheers from ireland ,i just do simple porting on my saws but you really explained it in a simple way .thank you.

[@andrewslagle1974]

Thank you for the tip ,your a big help !

[@mechanech]

Thank you John!!!

[@Witschor]

Thanks John, i will check that on my Testsaw and rethink that to understand exactly the Functions. Is that the Point when a Saw barks back through the Intake , caused of to much intake Timing? I will check that on different Saws that show up in my Shop. Thanks a lot Man!

[@MrHuntermikey]

Awesome info big Thanks John

[@meskalin64]

So what if you add windows to a piston?

[@Op1zilla]

Thanks for that Tasty piece of info 👽👍

[@thomaslindroos1667]

This is gold thank you very much John

[@patrycklealoliveira8106]

Friend, good morning! From Brazil. I have a big problem with a Chinese Thorq 62cc chainsaw. I tried to start it and when I pulled the starter cord it was very hard. I removed the spark plug and it turned the engine free when I pulled the string, but if I put my finger in the hole where the spark plug goes, the piston is completely locked as if it were vacuum or excess compression. Do you have any idea what it could be? I disassembled it and the connecting rod, crankshaft and bearing, piston rings are good. The piston had carbonization on the top but I cleaned it and also decarbonized the cylinder. I can't find the new cylinder and piston for it, as they are 48mm in diameter. I only found 43mm and 45mm for sale. When I assembled it, I still had the same problem, as if it were a hydraulic wedge, an excess of compression that doesn't allow the piston to descend or ascend freely. Can you give me any tips on what is causing the problem?

[@jeffwooton7138]

Thanks for sharing. Hotrodders will hotrod!

[@ericnicol2616]

Great video!! Thank you for that information!

[@chadmeador1557]

Hey Eric! Just subscribed to your channel as well! 🤘

[@lessmith4974]

Quality info,cheers, much appreciated.

[@JohnWilliams-junglejohnny]

So my 362 I’m doing with meteor jug and piston . When intake cracks open . Bottom of bottom ring is just at roof of exhaust ,your thoughts on what u would do .squish is .024. And what timing numbers do you feel are good for this saw

[@chadbrewer6882]

Dude, you’re on KZbin; Never be concerned to ask for a thumbs up a like or subscribe. That’s how you get paid. That’s the name of the game and you provide so much knowledge for the hobby. Obviously you do you, but ask for that thumbs up/subscribe! Just my two cents and thanks again for this killer info! Took a lot of mystery out of why we do and don’t and especially just reconfirmed why I’ll never buy aftermarket Chinesium. Cheers!