Why does my pull start jerk back?

[@frankie7508]

Probably the best overall explanation I have seen so far after watching hundreds of youtube videos regarding timing failures and causes. Great job!!! 👍👍👍.

[@MNDashcam]

Glad it helped

[@stewartbruce2409]

You certainly have the ability to convey your tutorial with good photography, and an excellent explanation of the things to check. Some people know how to do something, others have the gift of a teacher to pass on their knowledge. Thank you for an excellent video.

[@MNDashcam]

Thank you for your support!

[@robstone5333]

Thanks for taking the time to make this video. Very helpful and articulate. Also appreciate the perfect volume level and NO annoying background noise or distractions.

[@michaelhoit9186]

You earned my respect by this video. A few days ago I bought a Briggs & Stratton motor that did not run I’ve been brought it home and it did the stupid kickback thing and everything I found on the Internet said it was a woodruff key in seeing this about with the camshaft in the crankshaft lineup helps a lot thank you man have a great day

[@leoscustombuilds9717]

This was extremely helpful!! This was exactly what was wrong with my go kart engine. It was off by 1 gear tooth.

[@leocruz3037]

This answer my question, thanks very much for taking your time. The key on my 6.5 Toro is ok so I will take it to the Junk yard. You explained it very well and is not worth it for me at this point.

[@harvindersingh1160]

I learned something new. Thanks!

[@Fridgemusa]

Also sometimes a failed decompression governor or worn out exhaust lobe or incorrect exhaust valve clearance can cause the same problem.

[@FastenDeezNutz]

This is really good info. Thanks man

[@BlackieMiles1]

Great explanation!

[@IamtheActionman]

Very helpful, thanks man

[@IamtheActionman]

New key and my blower works like new again. Thanks a bunch

[@CadeCay]

This video was really helpful. My mower (which im using for a project) is always pulling back every few pulls and it backfires out of the carburetor so I'm gonna check the flywheel for allignment. (ive opened to crankcase for modifications and the timing is good there)

[@johnpaulbrehm1883]

Phyren Your fly will key could just slightly be out just a couple thousandths from hitting a rock that’s what saves your crankshaft from getting twisted aluminum flywheel key@ backfire ? it’s our of time. You don’t need to go all the way into the crank case you just need to check your fly wheel key for the slightest crease or line in the side of it which is under your what are they call it your starter clutch little thing on top of your fly wheel shaft that spins did your shroud cover attached too

[@DurhamHumor]

You are good. You know how to give instructions

[@brianmiller1313]

Thank you thank you thank you.. saved me after spending a ton of time killing my hand having pull yanked out… took both the mower I threw on the parkway last night and another we have had issues with for far too long. Did just as you said only fabbed some aluminum keys and bingo! You saved me lots of energy, some pain, some aggravation and a bunch of money! No more need to buy a new one.

[@ronnieayers6956]

Good info, thanks!!

[@gamking7987]

after searching for tons of videos finally I got an answer for this problem

[@datacreed]

...or a mini bike! :) Thanks - good insight - I might go exploring internally for this!

[@TheJoker-wv2id]

Thanks for the video it’s very helpful

[@richardstell8099]

Thank you sir ! 😀

[@ZombieDaveAZ]

For the newbie mechanics out there starting to work on machines like this. the lightweight aluminum flywheel is complimented by the mower blade. Trying to start a mower without the blade will will also cause a snap back on the pull cord. if the timing via the sheared key is off by just the right amount it will loosen the blade enough to make it unbolt itself and drop on the ground. very good video thank you.

[@ballzmahonee5645]

ulitepilot so how do you get it to run, without breaking my arm again? my go kart has push mower engine and every couple of pulls it jerks off, other than that runs fine, like starting motor cycle?

[@ZombieDaveAZ]

Steve Townsender Different model engines have heavier flywheels or larger diameter for the use they were intended. Its all about momentum. small 2 and 4 stroke motors w/above average compression will use a compression release or mechanical device on the camshaft that holds the exhaust valve open a couple .001 til engine starts then centrifugal force holds the compression release out of the way. these types of engines are usually designated by 'easy start or easy pull'. others have a spring do the work. hope this helps and I like the way you make your videos. thumbs up.

[@zazarays]

Didn't realize that about the blade. I've been experiencing this with my Tecumseh 3.5 after sharing the Flywheel key. I put an eBay Chinese carb and ignition coil on it and thought either the gear was jumped like he says in the video or the coil thru my time. I just put the blade on and have no kickback. Any idea why i would hav smoke coming out of the Crankcase breather tube?

[@ZombieDaveAZ]

Hey Pancake, smoke and or oil out the breather is USUALLY too much pressure getting past the rings. Different mowers have different pcv methods so I cant just say its this or that. If it was on my bench with those symptoms I would run sealed air in the plug hole and listen for leaks. good way to check for "blowby" and intake valve seat. some mowere have compression release which can give a false read that the exhaust valve is not seating. so if possible put constant low pressure air in the plug hole. remove dipstick and listen for air there. thats rings and not good. hope that helps.

[@zazarays]

Yea just read about BlowBy -_____- Looks like i need to tear the whole motor down and replace rings. Its supposed (maybe im wrong about this after looking at wtf a pcv is) to be Sucking air in thru the CrankBreather but, it's blowing smoke out. Not real bad but, noticeable. Also using a 22inch blade now when it came with a 20inch

[@SmoothCriminal69]

Thank you! The same thing was happening on my Coleman CT200U mini bike.

[@datacreed]

mine too - August 2019 - did you fix yours??

[@hectorvillalpando5675]

Thank you sir

[@banksidefishing7575]

My generator is doing this and breaking the rope! Thanks for the info even though it's been here to see for five years!!!!! 🙋🏾‍♂️✊🏾🤭

[@MNDashcam]

Hopefully this helps solve your issue. Let me know how it goes 😁

[@kiketurcios4665]

Good job amigo it help me a lot

[@capone3167]

Thank you!!

[@shaunthompson1935]

Dang bud. That's got to be my problem. I replaced the piston and con rod and camshaft and coil. All original parts and matched the timing dots to counter balance and cam.. Never thought about the damb crank itself because it still has kick back. Damb near break some tendons in your elbow. It's got to be the crankshaft. Gonna replace it tomorrow. This project was killing me because I know my valves we're seated good after I lapped them and set valve lash to factory cold. Good deal.I know this is old but it's still good help

[@MNDashcam]

Did you get it working?

[@kaiwong2666]

Thanks!

[@tudocervera3764]

awesome info my friend!

[@curtisdonnelly7946]

Thank you

[@oldguy8177able]

i just bought a weedeater with kickback what i did pulled it apart found a lot loose screws but main thing i re gap ignition coil gap and tightened it,it worked run fine now

[@ronaldjacobs8561]

thanks for this video

[@michb7414]

Much appreciated! I guarantee that is my problem, We have a walk behind four-wheel-drive Husqvarna I'm going to get attempt the repair myself. If i cant fix it its going into te dumpster and i will but another decent mower propelled. Im leaning towards battery starter will pull backup. Any recommendations would be appreciated! Srlf propelled walk behind 4 wheel drive min 5 hp prefer more HP. I hate itcwhen they stall cuz of tall grass. What about Honda?

[@Atypicool]

Thanks for the vídeo

[@USMC_BABE38]

We're having the same issues with or leaf blower it's locked up and I can't pull it more than once or twice it reist being pulled to start it I can't remember if I was off timing or it's locked up and need servicing

[@philliphall5198]

Some people don’t need to even try to fix them because of all the damage they cause besides not fixing the problems

[@bashirfayad]

You are very smart and well spoken for person like me slow therefore I solution you. Unlike KZbin hire some Chinese to demonstrate.

[@johnlibonati7807]

Does a generator have one of these? My generator pull cord yanks back. The valve clearances were messed up because the exhaust valve nut was loose. I set the clearances to .007 but still get the snap back. Thanks.

[@lilniggagillie9355]

thank you.your video was helpful.

[@gamecaster5002]

I was thinking of welding my on as the shaft is like the second one you showed do you think it will work

[@seanwalker5157]

thanks it helped ok now

[@johnpaulbrehm1883]

First check your intake and exhaust clearance I believe intake a seven thousands exhaust is 11 Th with a feeler gauge. And if it’s backfiring usually it’s the exhaust valve being the valve who’s stem is visible through your muffler port if you have to get into the guts of the mower your must not likely not gonna fix it at home and you’re better off to pay someone to $80 an hour shop for you to have them do it because it will take them precisely one hour to disassemble split the case and pull that most likely you’ll mess up the case when you try to split it you don’t have to go as far as he showing.. because a feeler gauge will tell you whether your lobes is worn or not.. But I could be completely wrong and not remember correctly but I don’t believe so dad was pretty stringent

[@user-dx7gh8qi4o]

Very good, but I am dizzy now, lol

[@not41zself]

How do i adjust vavle lifter screws on ohv engine?

[@musicsubicandcebu1774]

Thanks

[@steve8803]

I bought a new honda snowblower 5 years ago, and the cord has occasionally ripped out of my hand since the first season. One time it ripped so hard that the handle on the rope exploded when it flung back. What would cause a snowblower to shear the flywheel key? I have busted a few impeller and auger shear pins. Is there an easy way to check the flywheel key without much disassembly?

[@MNDashcam]

If you remove the nut on top of the flywheel you can look down and see if the flywheel and the crankshaft are in line with each other.

[@davidgordy1]

You can also Lap that shaft and flywheel and use it even without a key at all. Just Torque to 65#

[@nolan_shaga]

This was happening to my push mower and the pull cord pulled back with so much force the handle hit my hand and caused bleeding and external bruising. I was faint for a while and had to lay down..

[@lol224455]

UPDATE:1 year and still cranks within the first 2-3 pulls. Probably will buy another when this one finally does bite the dust kzbin.infoUgkx43QMbQqu67IZadu9ou8Sg1BdrunMRNqX . No issues at all. Very happy with it.UPDATE: After 6 months of use and over 70 uses I would still highly recommend this pressure washer. It does vibrate a decent amount but never had it “walk” like others have mentioned. No oil leaks, still seems to run like the day I bought it. Still cranks within 2-3 pulls every time. Very happy with my purchase!Have used it about a dozen times now. Plenty of power, cranks up on 1-2 pulls every time. My only complaint would be I wish it was a little taller to make it easier to walk with it (hits my ankles a lot) and that the two hose connections were a little further apart but it hasn’t caused me any issues. Seems to run a good 1-1/2-2 hrs on a full tank, overall a well built machine and definitely worth the money in my opinion.

[@videobobdammit4818]

The problem with my chainsaw was that it was stored incorrectly on it's side. The lower end was full of oil from the bar lubricator. Had to spray WD40 into the exaust to thin and drain it.

[@coondogtheman]

I have a yard man/john deere push mower hybrid that I made. Not sure of the make of engine but one day I went to start it and I'm the kind of person who takes care of my engines. I checked oil and gas and then primed it and then pulled it and my engine seemed to have this issue and the cord jerked back hard and I hurt my wrist. Will start with the shear key. Are they all the same or do they vary from manufacturer?

[@MNDashcam]

They do make specific sizes but any small engine place will have a universal assortment variety pack. Either get the right size online or at a small engine place or you can even take calipers and measure the width of the groove in the shaft. I think places like Harbor freight might even have an assorted variety pack.

[@gfriedman99]

Also if your coil is not positioned correctly can cause this problem.

[@steelavocado1]

What if you just weld them together. I know it would be bad, but I can’t find any key for an old chainsaw I have

[@manman3015]

Crank is steel flywheel is aluminum. They won't weld. If you can't find one that fit buy a oversized key and carefully file/sand it down so fits good and snug

[@Anto-kz5hk]

I fixed the flywheel key and after I put it all back together the mower started pulling the cord out my hand. 😢. Idk what is wrong.

[@oldguy8177able]

listen i'm no expert but just sounds ridiculous if the timing was out it wouldn't start anyway I had kick back on a stihl weedeater it was the spark arrestor plus exhaust loose so difficult to start once all fixed no more kick back,the kick back is caused because exhaust gas can't escape if exhaust blocked so you get the kick and its painful

[@oldguy8177able]

@osu67 dude i took arrestor out guess what no kickback

[@herbtwiss8866]

Curious. If the mower runs fine once started is there still the possibility the key is broken or the timing gear shifted?

[@ZombieDaveAZ]

The gear shifted NO. Partially sheared flywheel key? It happens all the time. Still runs but the occasional snapback will pop up and decreased performance.

[@1up1up11]

When my flywheel is on the motor and i manually pull it, it sometimes feels like it doesn't wanna turn and gets stuck, is it supposed to be moved freely?

[@luispar100]

How do I remove flywheel?

[@lonestarangler8407]

I have a a Stihl BG86 blower that I found, and the pull start cord is Really hard to pull when the Spark Plug is in. But once I pull out the Spark Plug, it pulls really easy as it should. When I put my thumb over the spark plug hole and pull on the cord... I could feel suction and push from the compression. any advise on what would be causing this?

[@norbertnagy5514]

Could be valve timing

[@braidenbatesmatthew]

my go kart belt tension and pull cord are both stuck

[@roseanncloskey]

Excellent Trouble shooting 1/21/2023

[@boblynn1926]

same symptom but on a new 2 cycle generator. and it happens with the spark plug wire removed. do you think it's the woodruff key?

[@MNDashcam]

With the spark plug removed, there would be no spark and explosion to send it back down early. You might still have a timing/compression release issue going on though.

[@hp11208]

Mine works, but pulls back sometimes.

[@ProfessionalDad]

CHECK YOUR VALVE CLEARANCES. THAT WAS MY PROBLEM. NONE OF THESE OTHER SUGGESTIONS

[@daryllect6659]

The flywheel key is sheared.

[@beebob1279]

How does one fix the chainsaw?

[@oldguy8177able]

addition what I mean is when trying to start it when cranking it you get a kick back it exhaust blocked I mean it wasn't blocked completely maybe 80percent

[@gfriedman99]

Interesting

[@richardgrower9580]

Mine is a chain saw.

[@paulblackburn931]

It could be a chain saw!

[@zazarays]

Thx dude. Heres hoping this is why the push mower isnt running. Rather not spend 150$ on another one.

[@MNDashcam]

Pancakebut let me know what you find out. Craigslist is full of cheap or free mowers that just need the carb cleaned.

[@zazarays]

Yea its only very slightly bent out of line. Less than 1/16 inch off. it used to run Even after i hit this stump and ruined the blade. But, the frame was so worn out with the wheels bending and stuff i quit using it. Here is Key www.ebay.com/itm/Flywheel-Key-For-Tecumseh-611004-/231694045184?hash=item35f20a9000:g:kwgAAOxy3NBSjj0c I just put it in another frame put a new ignition coil, carb, blade on it. BTW ive been mowing both my yard and my mothers with a weed eater for like 3 years now Lol. Cuts real low and looks real good imo but, gotten hard on my back

[@zazarays]

Fired right up after replacing the flywheel key! Honestly i didn't expect it to start. Idk what town u live in but, the cheapest push mower i found in Muskogee, Oklahoma was 50$ on craigslist. Never really used craigslist before tho Anyways thx for the video bromandude

[@MNDashcam]

Pancakebut happy to help. thanks for the support

[@tangiwaiedmonds8894]

steve-o

[@jellysleeks9428]

Snapped back and gave me 6 stitches on my left thumb. Not pleased

[@stevioAda]

Incorrect valve gaps causes this two engines iv worked on had no gap caused recoil and back fire

[@manuelsalgado8510]

Im gonna try this on my auger, it pulls back really hard on my that it hurts

[@benjoseph8387]

Heard if u overfill the oil, it gets into the combustion chamber...causing the pull back rope problem...or even if u tipped motor too far and oil spills into the c.c. ...ever hear of this?

[@benjoseph8387]

Good video...no wasted time/words like most diy videos...👌

[@vexstatv8011]

Ya but it wouldnt start if it was filled that much in the chamber or it would smoke alot

[@gfriedman99]

That’s real interesting. I got the kickback problem and noticed the oil was like 5 inches above the full line on the dipstick. You might be onto something.

[@mattgavel6572]

Too much oil will hydrolock your engine and can cause a kickback. Drain it till it is just at the full level and it will eliminate that problem. If it doesn't it is time to check other things. Valve clearance and then if that don't fix it flywheel key. If it's none of the above the problem is internal and will require you tear into it.

[@TerraNovaSpirit]

🙏🏼❤️🌸🌺🌷🌻🌼🌹❤️🙏🏼

[@717carloss]

Mine jerks back but it still starts and runs good

[@Pothead2005]

Shit my minibike did this And I’m scared

[@seven73ify]

Can you get the key at hardware store

[@needhelp2453]

Yes, sometimes you can.

[@ProfessionalDad]

My generator kicks back hard & sheer pin is fine

[@MNDashcam]

Pray

[@djmystery7235]

What if on my quad my flywheel blew apart and my stator blew up into oblivion😂

[@MNDashcam]

Dj Mystery then you have bigger problems lol

[@MNDashcam]

That's actually very common with the older style where the magnets are simply glued into the housing.

[@christiantaylor6867]

This makes no sense because I just replaced the crankshaft on my 10 hp tecumseh and the new shaft has that key piece!!!!!..its not broken off!!!!!!

[@JorgeVonVogler]

What about valve lash

[@MNDashcam]

What about it?

[@StanOnDemand]

On my MTD push mower, the starter motor won't turn with spark plug inserted. As soon as I remove it, it turns freely. What can cause that? I've removed the spark plug and pump out oil out of cylinder and piston wall. Have no idea what else to do.

[@MNDashcam]

There could be a couple reasons for this. If the spark plug is the wrong one, the piston comes up and hits the plug and it can't spin freely. If the plug is not interfering with the rotation, likely either the battery or starter is weak or the connections are loose, corroded, or dirty. They need to be able to overcome the compression created and should be able to do so when performing properly. Check to see of you can get the engine to rotate by hand with a breaker bar with the spark plug in. This will give you some direction.

[@StanOnDemand]

@@MNDashcam with spark plug in, motor turns a little in some parts. But as I continue to turn it by hand, it gets to a point when it gets stuck and requires a lot more force to spin. Once it passes that point, it's a little easier to spin until it get stuck at that point again. And this goes on and on.

[@MNDashcam]

@@StanOnDemand That is normal. There should be some resistance when it is building up compression. If there is no mechanical resistance like a clinking noise at any point, then you likely have a weak starter or battery then. Can you try jumping the mower off a car or charging the battery?

[@StanOnDemand]

@@MNDashcam it's a mtd self propelled mower, not a riding mower. I don't believe there's a battery. The model of the unit is 12A-A13k729.

[@StanOnDemand]

@@MNDashcam I mean, what happens if you have too much resistance/compression? The pull cord is really tight. I pull really hard on the cord (get to about half way) and release, and pull and release (and so on and so on) till I reach a point where there's less resistance and pull cord all the way. I do this a couple of times till the mower starts. When it starts, it seems to run fine.

[@gadsdenguy9783]

Did i hear a racoon in the background?

[@gfriedman99]

I thought was some kind of bird.

[@mili4344]

compression regulator....

[@gfriedman99]

What anout it?

[@randomtech6115]

Mines lined up and does the same thing any suggestions?

[@johnpaulbrehm1883]

random check your Fly wheel key

[@Sianodak47]

No counter weight on the shaft

[@johnpaulbrehm1883]

I like your video but you show it being quite a bit off it’s just Hass to have a slight groove in the side just an impression on the fly will key will cause it to not start first or second pole sorry that was a small engine mechanic for over 20 years so I spent plenty of time change and fly I will keys are usually check the blade first if you see a good Nick in the blade the most likely there’s going to be a Nick in your flywheel key and you can’t always tell by looking at it from the top sometimes you have to pull it the start clutch off

[@christinahornback999]

Or it could be valve springs btw I'm ten

[@DavidMartinez-oc7nj]

why does your age matter

[@Hello-rw7ry]

Do you have a pet Racoon?

[@johnpaulbrehm1883]

Compression , or out of time

[@stevenellis3147]

B

[@amerikanstafford]

++++++

[@albujeyash2580]

It's nowing as flywheel keys don't try to throw names out there

[@EarthSurferUSA]

Woodruff keys are made out of mild steel, and much harder than the aluminum flywheel, but softer than a crank shaft which is usually hardened a bit. They are not "sheer keys". Unlike a boat motor prop, this application does not need a sheer component. I am sorry, but this is the second vid I have seen of yours that is a celebration of mediocrity. I know you can do better. It just takes a bit of formal education.

[@iconoclad]

It's "shear" not "sheer". Some irony here. There's no reason to suggest that a woodruff key can't also be a shear key.

[@ZombieDaveAZ]

I disagree 100%. The key provides a dual function. It is a "sacrificial"part. Its primary purpose is to time the ignition to fire at the proper moment. Secondly it provides a safety to protect the more expensive internal parts of the engine. Starting at the flywheel journal of the engine. On a mower there is also a slot for a keyed blade mount adapter. Its dual purpose is have the blade spin with the engine and designed to shear rather than destroy the PTO journal.