Chainsaw cutaway # 4: 2 stroke air leaks explained

[@brittainwright1]

You taught me more about 2 strokes in the 4 cutaway series videos then I learned in the last 40 years.

[@micahgerdis1008]

I 2nd that .. very good overview.. thanks

[@tysauce1986]

I can't understand why people actually down vote any videos. Let alone a video like this one. It's straight to the point, it has no ads, and it doesn't promote anything in particular. It's a factual video. And a well done one at that.

[@skitidet4302]

"I can't understand why people actually down vote any videos."
You basically answered yourself when you noted the absence of a list of things that people could find disagreeable.
But I agree, I can't see what people would find off-putting about this video.

[@maplebones]

Contrarians feel better about themselves when they put something down. Accept that it's just the way it is, and think no more of it.

[@mijnbeeldscherm]

I agree

[@carlodonnell146]

Mary Mary quite contrary..............@@maplebones

[@larryhardin3985]

Wow! Thanks. I repaired my 026 by replacing the top end. I tried the same thing on my brother's 280. It started, idled well, but got very hot. You just explained what was wrong the whole time--I replaced the wrong part. Getting too hot must have been the original problem. You are a super teacher. Keep going.

[@charleswilson577]

Don't think the cutaway can be beat plus the way you present things. Top notch young man.

[@hphillips7425]

The chainsaw cutaway series has helped me a lot👍

[@sonofthunder.]

these videos along with west coast ,are great showing the areas of repair for pressure and vacuume leaks,i finally got a mityvac type tool ,i hope youll keep showing ,with soapy water etc,im learning alot,THANKS

[@gregorydobson4307]

A video is worth a thousand words. When I ran my 2 stroke dirt bikes back in the 80s never knew how they worked till the cutaway arrived. 👍

[@charleswest3008]

Superlative explanation. My old Stihl 041AV runs super fast at idle, and despite putting a rebuild kit in the carb it still won't runs fast, almost wanting to run away at idle. Now I know why. Thanks man!

[@oby-1607]

Man, that was priceless. Very honest explanation of what kills our saws.

[@AN-jz3px]

This channel has renewed my interest in messing around with Saws.

[@geopolitix7770]

Ditto... even though I know a little knowledge is dangerous but!

[@Anthony071177]

Great video bud, I definitely learned alot on the detailed process of the internal motion how you broke it down. Thanks a bunch.

[@justinf1343]

Thanks for sharing. I'm getting a stone saw shortly, and this has been very useful.

[@robperrin9497]

The cut away series is awesome. I've seen a few animations of how a 2-stroke works. But actually being able to see inside the engine while you explain what we're seeing. Game changer for sure. Thanks man.

[@carlodonnell146]

learning that the air-charge in a 2-stroke is compressed in the crankcase is most strange to me after learning about the 4-stroke where it is compressed in the cylinder; it takes some getting used to but once you understand, it is easier to diagnose any problems.

[@MrJoeakd]

i love it. proffessor tinman. " if you refer to my previous video , piston ported chainsaw".. you are truly a good dude..

[@bobblenuts]

Using the cut away really helps me understand what's going on, & you explain & demo it very well. Now that cold weather & shorter days are here, hopefully I will find more time to watch some of your old videos.
Thanks & fantastic job with the air leaks! 🍺🥨🍺

[@andrewbock1575]

Cant thank you enough for this cut away series! I have always wanted to port a saw and work at a cnc machine shop that will allow me to use their cnc equipment for my own stuff on my own time. I never quite FULLY understood the nuisances of two stroke port work until seeing your videos. I have an old 026 that will be my guinea pig before moving on to my bigger saws. Cant thank you enough for these new videos and look forward to more of them before proceeding with my build! Keep up the great work!

[@geoffluck]

I can only say thank you, you really are getting this explained perfectly, and in a simple way for folk to get to grips with.

[@johnub1143]

Great concise explanation, thanks. There are many overpaid university leturers who would do well to emulate your technique and style.
I'm currently experiencing an air leak issue with my boss' MS390...worn crank bearing diagnosed by repair shop and now started racing at idle...I suspect it does not have many hard days logging left in it...videos like this one help further my understanding of the problem and allow me to explain why we will require a replacement saw quite soon!

[@timknievel6407]

Your cutaway saw is the GREATEST!!!!!! It really makes the engine make sense to me.

[@chuckuu9294]

Tinmam great video again. Well explained. The cut away get tool thanks

[@BobKlimple-bt5wr]

Thank you for sharing this complete explanation i have ever received

[@constructionduru5195]

@Tinman thank you sir for another helpful and informative video! Really appreciate you taking the time to do these!!!

[@jerrykast7713]

Thank you so much. You are a really good teacher...

[@tonymayhew191]

I do alot of automotive work for my neighbors and friends, And when I hear a high idle on a vehicle that is computer controlled I know that it has a vacuum leak. The way I find the leak is by connecting a hose to a Colman propane bottle and crack open the valve and run the hose around the intake manifold, when i hear the idle go down i know that i have found the leak because the engine pulls the propane in through the hole and brings the air/fuel mixture back towards the 14.7-1 mixture which is referred to as a stoikect measurement known as a perfect fuel to air ratio that your vehicles computer is constantly searching for from the time you turn the engine on until you turn it off again! It works like a charm 😉

[@kevinswalley5644]

I'm 2 years behind on seeing this video, but dang glad i found it! Great video!!!

[@SlowBrow]

tx for the cutaway..it is really the best explanatory of two stroke real working...🙏👍so much tx guru🙏

[@martimlluch9]

Nice 2T engine cutaway series; thank you for your effort; good didactic presentation. You are a good person, take care. All the best to you and to your family !

[@dshurak827]

Great Information about the Crankshaft seals, Enjoyed the Cut out helped the explaining.

[@joshdurrant9247]

Another great video to the Tinman's cut away series! Keep up the great work and keep the awesome videos coming!👍👍💪💪😁

[@paladin44]

oh yes, you have a very nice vise as well!
love your videos, i'm learning alot from you

[@seather863]

Man these videos are great! 1:04 You know your videos are great when the fly wants to learn about chainsaws.

[@billybm0]

This is an awesome series. Thanks for sharing your experience and knowledge.

[@massawman]

Great use of the cutaway saw . Thank you for more great tips and information.

[@maplebones]

I know it's common language, but it sounds arrogant to me whenever I hear people say they 'built' a saw or engine. It can be rebuilt by renewing parts, modified or tuned, but to claim you built it is disrespectful to the engineers who through education and experience went on to the manufacture's plants where the saws we're designed and built. That is the hard work and I believe credit should be given where it is due.

[@grzegorz16100]

Nie zesraj się

[@robertgamboa4909]

Great demonstration with the cutaway. Thanks brother.

[@christopherkenny3488]

Man thanks so much iv alot more understanding of how any why things work witch is such usefull information.👌🏻 this vid and the other 1 like it great the fact im able to see all the working parts.

[@david92867]

I’m kina diggin the cut away saw educations!

[@harveybrooks1460]

Helped me lots to understand. Especially with the cutout :D gonna check these methods on my dirt cheap little poulan 2150. Keeps revving high rpm's 2 minutes of running.

[@robbiehogg1294]

Great video. 👍 well explained. The cut away chainsaw is well done 👏

[@simpleman4224]

Another excellent explanation!! Thanks for sharing your head full of knowledge!!👍👍👍👍🙏🙏🙏🙏🇺🇸🇺🇸🇺🇸🇺🇸

[@MrONHcP9]

Wow, so clear. Best explanation I've seen. Thank you so much!

[@KensSmallEngineRepair]

Fuel lines and carb shafts and gaskets too.

[@stevetheriault4164]

AWESOME TUTORIAUL BUDDY,GREAT EXPLANATION ,YOU MAKE STUFF NOT COMPLICATED WICH I LIKE EASY TO UNDERSTAND THANKS BUDDY ,HOPE YOU GET YOUR FIREWOOD ALL READY BE SAFE TINMAN

[@G-PA-2795]

Great job explaining bottom end air leaks. Thanks

[@reedswain5759]

I know this is not a new series but I just barely watched it. I'm an old guy... Almost 80 and I used to own a saw shop and you left out one of the sources of an air leak, the intake block under the carburetor. In fact this is a common defect on some of the Holzforma saws. If there's an air leak between the carburetor and that cylinder it will make the air fuel ratio all wacky and you'll get the exact same result as an air leak on the crankshaft seal.

[@user-eq2sd7lh2f]

Cut the plastic bottle into a tube and attach it to the air filter.
If you spray water on the right crankshaft with a shower, it will absorb the water and stop.

[@RG-wy1ol]

Thanks for making this video very helpful and educational 👍🏽👍🏽

[@sunflxwergamer303]

Great explanation!

[@jessehunter3052]

Thanks Tinman. Really appreciate the insight! Now i know what to look for on that 365!

[@noahschmartz2354]

just so well explained.

[@the1khronohs40]

Fantastic! 🤩👍

[@budgillett9627]

TREMENDOUS video!!!

[@rncboy2]

Something I have noticed since I rebuild more back pack blowers then I get to saws. When the crank becomes loose from the bearings and it has crank play from blower side to pull start side it causes a crank seals to leak when they do that the base gasket tends to go on both sides directly where the transfers are from the case to the cylinder resulting in the push effect like you are talking about resulting in fuel/oil buildup around the base of the cylinder but 30,000 hrs of 1 to 2 hrs of straight full throttle with maybe 15 minute fuel ups going from property to property doing leaf cleanups. They do have the exhaust and transfers a little weird at first with a squish of .062" with base gasket and .052 without ex ATDC is 110-112 transfers is 125-126 then I got to thinking how the bottom end is and how the carb is what the idle speed (2000 + or - 200 rpm) and max rpm (7200 + or - 200 rpm) is and that it's pretty well much under load all the time. Anyways sorry for the rant part completely different style of things for those then a saw. Same style air leaks though throughout any 2 stroke.

[@michaelwhiteoldtimer7648]

NOTHER GREAT EXPLANATION OF AIR LEAKS, CUT AWAY SAW IS GREAT

[@11bayrat]

Thanks for sharing. All ways learning and review ing. Big thanks

[@Finom1]

Tinman, Bless you for sharing your wisdom with us. Another amazing educational video. Everyone smash that Like Button and Share the video!!!

[@horaceinfiji]

Half way through this awsome video i realized i was thinking of chopping one of my old chainsaws in half......not so strange right? How come The Haul Back was thinking about how fast your hair grows🤔. Thanks a Million for the great uploads Tinman!

[@jonathanharsch3243]

Awesome info there thanks for the video keep them coming

[@fredhuang9223]

Very good!

[@frywheeler]

you're a genius.

[@tc6643]

Thank you for another great video! As a novice saw guy at best, I recently had a saw to fix for someone that had a scored piston and cylinder. It was not a straight gas issue. I did find that the carb was actually loose from the intake. My limited knowledge leads me to believe that could have been an "air leak" which limited the amount of lubrication from the fuel/oil mixture. I understand most air leaks are found in the bottom end but do my thoughts here make any sense? Thank you in advance for your help.

[@brucewatson1217]

Good morning I would like to know how much vacuum two check the seals on my chainsaw I do have a vacuum gauge I just don’t want put to much on them and blow them out. And how long will they hold Vacuum? Any help that you could give me I would appreciate it so much and I wanna say you got a great Channel keep up the great work and thank you have a great day

[@caterpillar1693]

Im sitting here watching this and by the way the cutaway series is straight gold i may of said that in the first video but anyways. I have a 48mm husqvarna cylinder in my hands at the same time. I know no this has nothing to do with the video, but i was looking at the plugs. Bottom line is i hear many guys say why are you worried about the spark plug so much. Kinda silly to me not to worry about it considering its a pretty important part of the combustion engine. What i was hopi g is you could do a video on why or why not it may or may not be beneficial to change your spark plug more often or less often. I run 3 to 4 differnt saws cut 15 plus cord of wood with each and i change them at least once a year and keep the old ones that are still good for spares. Personally im not claiming to be right or wrong just curious. Thanks for the great videos

[@tinmanssaws]

Hey thats a good topic and one that I've been asked about often..
Straight goods is I rarely ever change my plugs lol. Not sure if its the oil I use or what but my plugs are usually clean and thus I don't ever feel the need to replace them.
Just my experience, I feel its probably good practice to clean and inspect or replace plugs regularly.
Its probably because I have so many saws and none get a huge amount of time.

[@caterpillar1693]

Its good information no matter it makes people think. Thats the goal to get the gears turning isnt it, maybe not the goal but certainly one of them

[@bishoptrees]

Hey mate, we gonna see the return of the mighty cutaway? Just watched all 4 and it's really helped me understand what the hell is going on inside my saws! :)

[@holleyman1970]

Very good video.
Do you find leaking crank seals to cause hard start?

[@untestedunit7782]

I have two stroke quad, I’m about to replace the reed valve boot to see if that the air leak issue

[@olivierj.2435]

Thanks a lot. Great explanation

[@JoseRGarcia-JRG]

TinMan you rock !!! in the future please give us Husqvarna guys what you can on the 572xp..
thanks for the great lesson

[@marceldiseraad9977]

I have a husqvarna 135 (small saw)over here with a cranckshaft leak. I’m not looking forward to repair it but I will go and try it this summer. Any tips or how to’s to replace te cranck seal? It’s not the one behind the flywheel but at te side of the clutch/chain

[@jerrysmith9935]

Spot on as always 👍

[@IndianaDoug]

This feller knows what’s up👆 thanks for the content, good stuff!

[@kingfornjot]

Would a leak make it not start at all my carb seems to have no suction at all it has good spark and compression but not getting fuel to the spark I have cleaned all the jets and float in the carb

[@swordfish1120]

Is one of the symptoms of an air leak that a saw will start and idle, but when the trigger is pulled the saw shuts off (compression is high 160 psi and carb kit installed)? I have a Stihl 026 with this problem.

[@GEARHEADALEX351]

I like how he continuously stabs the seal 🤦‍♂️😄

[@richardparacuelles3612]

my yamaha outboard 90hp theres no vaccum occur is there any other solution?😢

[@David_Carlile]

Disclaimer: I don't have much for a mechanical brain. I am still trying to figure out why one of my 550xp (autotune) saws wouldn't idle, but if you started it with throttle engaged it seemingly ran fine. Let go of the throttle and it would die. It's the only time I've had this happen. It also lost compression at some point. Ideas of what may have caused that?

[@davidhawley1132]

How do you check and diagnose where the air leak is occurring?

[@tinmanssaws]

Vacuum and pressure test or spray the anywhere that you think may have a leak with carb cleaner. Carb cleaner will make the saw stall

[@donaldlewis9734]

Great Video. Thanks I think my McCullough's leaking around the carburetor...? Is that possible

[@tinmanssaws]

Yep theres a gasket between the intake block and carb.

[@ScrewdriverTUNING]

Love this content.

[@dakotafrantz4179]

So will doing a bas gasket delete cause an air leak??

[@carlodonnell146]

Does good compression mean that there aren't any air leaks in the crank case, or is it possible to have good compression and still have an air leak somewhere else?

[@tinmanssaws]

Air leaks generally don't effect compression

[@carlodonnell146]

so air leaks affect only when the piston moves downward and compresses the mixture in the crankcase but not above the piston because the ports are sealed off by the piston then?

[@farmerjoebrown2189]

Gold

[@thadstuart8544]

Who's the F'ing Man? Tinman is the F'ing Man!!

[@korodski]

🤠🤠🤠

[@ianritchie126]

Question for you to man, have you ever had anything to do with the stihl 4 mix engines ? I’m working on one now which has seized the small end and smashed the piston , every one I’ve seen or heard about has had the same problem but being a four stroke working on a two stroke mix , (50-1) it means their only being fueled every 2nd revolution .

[@tinmanssaws]

They are quite common around here but Ive never worked on one of those.

[@trwilkinson4623]

Wild guess, would it be better to run at 40 : 1, but still using a quality oil? Told by a chainsaw mechanic, if using the cheaper gas station oil, use at 25:1 or 32 : 1 max. Engines reputedly last a lot longer. Hope helps.

[@andyjones6361]

Mr Tinman
I have a chainsaw that belonged to my Great Grandfather. And I am going to 61in a couple days. It’s an old “Mono” saw .
I would love to get it running where do I start?
Thank you,
Andy

[@tinmanssaws]

Check for compression and spark. Then see if its getting fuel, if all those things check out try starting it.

[@jdatwood7086]

You considered having classes? I’m not aware of any class or program that teaches the porting fundamentals. Once you have the philosophy it could apply to so many different engines, nots just chainsaws.

[@apersonontheinternet8006]

Thanks!
Want to do points sometime?

[@RuralLivingwithJesse]

My 461 has a brown piston when i look on the exhaust side is that normal for a stock saw

[@zzzgz5]

At least to some degree, that is normal. The brown tinge you're seeing is basically carbonized oil. On a saw with a lot of hours it may be worse due to accumulation over time. When we used fuel/Oil ratios of 16-1 or 32-1, that would happen sooner, but modern oils probably less so.

[@trwilkinson4623]

Bought an abused Mac 335, spares or repair. Muffler screen full of carbon. Side of piston almost black. Top of piston coated with carbon. Cleaned muffler,by soaking in caustic soda solution bath. Be careful of chemical burns ! Set piston so exhaust port closed, sprayed some " Mr Muscle" cleaner through plug hole & left for hour. Tipped out & repeated. Most of carbon deposits removed.
Added 5 ml of white spirit into a litre of petrol, then mixed fuel at 40 : 1. Ran the saw through several tanks, then removed muffler to check the exhaust port & piston wall. The discoloration had gone, looked almost like new.
Use at your own risk! Just it appeared to do wonders for me.

[@pm270100]

ar mate not bad lol