BRIGGS AND STRATTON LAWN MOWER ENGINE REPAIR : HOW TO DIAGNOSE AND REPAIR A BROKEN FLYWHEEL KEY

[@johngardner2807]

BRAVO, Jeremy ! I'm also a small engine tech,(22 yrs),and I've watched other videos(some were "pros"),and very few used a puller! Most just "pry & pound",and don't seem to grasp the damage they can do,that way ! From one "old-schooler" to another: WELL DONE !

[@frankmayne9377]

From one small engine mechanic to another, excellent advice. Please use the required zinc flywheel key. Never use steel for any reason. Guy from my hometown went the cheap way and used a cut horseshoe nail and the flywheel exploded after hitting a tree stump. He lost half of his right leg from it.

[@kevinmurphy3290]

Just want to let you know that you are about one of the best teachers I have found on youtube.

[@Serverisme323]

For a small engine mechanic that only knows the basic on how to start up and cut the grass this is a great way to learn how to fix the common problems over the motor backfiring through the carburetor and muffler and basic intake if engine repair.

[@luckydog-287]

8 years later.... Thank you, very much!

[@mikewhite3123]

Been a machinist for a long time, mills and lathes go through keys like that, I get leeway material by the foot, cut it and use it, think like 2 dollars a foot or so, mill table power feeds always sheer when the table is locked and they hit the rapid feed, thanks for the video

[@gerritdaems8879]

I wish I had seen this video two weeks ago. Motor was backfiring on me and it left me with a lame wrist for 5 days. Still, I kept trying to start it and ended up with a broken starter pulley, a broken bladeholder and then I broke a teeth of the flywheel while unscrewing the cup. Yes, I noticed that the two gaps in the axle and flywheel weren’t aligned but i wasn’ aware that there should be a ‘key’ in that place. Thanks for this useful video. Now I only hope I can still order the necessary spare parts.

[@amajorseven]

Thanks, your video helped me repair my engine. Finally it started easily.

[@fred306801]

I was going to ask where you got that puller ? Seems I am not the only one who wants to know where you get all those wonderful tools. Thank You for making these videos. You have helped me a lot.

[@639Beaver]

I like the way you instruct, you tell what, how and why. I thoroughly your teaching video. Thank you.

[@philliphall5198]

Merry Christmas 20200 I’m bored and looking back to old video AllWAYS fun to watch them Thank You’ll

[@Lovinflyindrones2022]

If other people feel like they can do better making videos I tell them to get out of it I think you do a very good job and a thorough job making your videos thanks for your hard work and dedication

[@aaroncole7736]

Good videos man. I can't believe all the folks asking so many questions.

[@robert574]

I had the pull rope out of the loop on the side of the handlebar and when I pulled it, it jerked back and ripped the handle out of my hand and then cracked it like a bull whip on the back of my hand. Man, did that hurt. (Picture someone using a bull whip with a lawnmower handle on the end). I always use a glove now to start the mower. Yes, the key was sheared.

[@handheldgarage3297]

I loosen the nut, spray PB Blaster on the shaft where the key is, pry up on the flywheel with a screwdriver and hit the nut with a hammer and that usually pops the flywheel loose.

[@RSS2100]

THANK YOU! This worked perfectly and my mower runs again.

[@kylealcombrack8274]

Explained perfectly. Thank you.

[@THEMOWERMEDIC1]

Yes. As stated in the video it is very important to clean the engine and the flywheel prior to re- installation

[@jonathanmayo1822]

I appreciate your work and thanks! Have a Toro self propel with a Brigs and Stratton engine. Quite suddenly while mowing it started a mettle on mettle rub. Engine itself seems to be running at speed, started with normal effort, not backfiring, etc. Did not appreciate that blade hit something, and the blade itself is not rubbing. Manually spinning the blade did not feel resistance or a rubbing sound. I went through the process of removing/reattaching blade assembly anyway (rule out the obvious) but no joy or obvious defect. The sound seems to be coming from above the deck not below. Was wondering if it was the key or flywheel but not your description of backfiring or pull rope resisting, etc. I cleaned around the engine, confirmed that there is oil, etc. I have just about enough small engine knowledge and enough tools to be dangerous. Any suggestions on what I should be looking for?

[@wtbm123]

I like that Tach. No wire to wrap I like that. Using that tach and the set up of it would make a interesting video.

[@THEMOWERMEDIC1]

your right.....the key is just an alignment tool basically.......once you torquge the flywheel down you could actually remove the key and it would stay in place for ever untill the mower hits a pipe, root, rock, ect

[@billt.murray9050]

Great video Jeremy. My crank on a 3 year old Sears Craftsman gas powered lawnmower with a B&S 190cc engine broke yesterday and the blade flew off taking a chunk out of my mower's deck. Any videos or advice on how to change the crank. Engine and flywheel key still in great shape - mowers still runs great. Event was a little scary.

[@wcjcnc]

Instead of a wheel puller I use an air hammer. I remove the bolt holding the flywheel on. Set aside the washer or the pull start cup or what ever the mower has between the bolt and the flywheel. Then I put the bolt back in and screw it almost all the way down. I have a round tip attachment for the air hammer. I put it against the head of the bolt and pull the trigger. Just a split second and the flywheel pops off. Much much faster than using a puller.

[@Lanninglongarmmowing]

You could use torque limiting extension to torque down the flywheel using an impact driver.

[@FISHINGWITHTITO]

I have 2 craftsman lawn mower's.they both want start. I changed the spark plugs cleaned the carburetor.do you think it's the spark plug core

[@Tjousk]

In my experience, keys fail when someone runs the mower over a large rock/cement - stopping the engine far faster than it should stop. I don't think it's cheap engineering to use a part that will sacrifice itself to save other parts. Is it cheap engineering to use fuses in electronics? I do agree that they should tap those holes though.

[@stephenfestus9268]

Great video....very informative...I'm assuming the most common cause for breaking a key is by hitting an object, or do they wear out with time?

[@ScottywoddieDo]

I would like to know the easiest way to replace the gas line is located directly underneath the flywheel to the carburetor mine is dry rotted and leaking please let me know thank you

[@bolens733]

Would be a good ideal to clean off the engine or does it matter before reinstalling the flywheel.

[@THEMOWERMEDIC1]

the rope trick is fine just make sure the engine is at tdc on the comp stroke so you dont bend a valve

[@0011clem]

A flywheel key for $1 is a great deal. over here we pay through the roof for any little thing from a mower shop. example.. airfilter for 3.5 briggs $11 . fuel primer bulb and plastic base plate $ 12 , a cirlip for the wheels costs $1 just to name a few . I have not bought a flywheel key , but I would imagine they would be $8 or so . I would be thrilled to get one for $1 . mower shops here charge like a full blown motorcar workshop .

[@markdutschke7733]

Jeremy, I have a 14.5hp Briggs OHV engine. Engine is blowing oil from crankcase to crankcase breather and into the carburetor. What usually causes this? Thanks Mark D.

[@warrenr7591]

You should tell people the first thing to consider is; if the mower was running well and you struck a stump, large rock or clump of dirt and killed the engine and then the mower is hard to start or won't start or difficult to start then the flywheel key is the first place to look. PERIOD!

[@E85_STI]

Yes exactly and I literally just found out about this today and you are the second person to mention this.

[@michaelgonzales7655]

@@E85_STI correct!

[@Eeropolvasti]

Good, easy job! Couple questions: What is correct torque, when you open engine, that block/sump cover, with 6-7? little bolts?? And is valve clearance pretty much same in 3.5/4. and 5 hp B&S engines?? What is it: intake/exhaust?? And one more question: how do you adjust that: grinding valve stem??? Thanks a lot, youtheman =)

[@rocky7983]

Do you go to a lawnmower repair shop to buy the key ? or did you have use Home Depot/sears/ Loews.....

[@micahobaca]

If the flywheel key is OK what would be the next issue to look for?

[@anthonygrant815]

My old flywheel key got sheared and I took off the flywheel and broke it in the process. I ordered another flywheel and key but the flywheel looks different . The new flywheel has something a little extra on the bottom and it may be a tad bit taller in height. The one I originally had looks like the one in this video. I just wanted to know if it really matters?.... Also it still makes the same noise when I try to start it. Like a cling/clanking noise? Help!

[@bobhaddock957]

had a sears riding mower with Kohler engine and wouldn't charge. finally after much taking apart and trial and error, pulled the fly wheel off and the magnets had come off of the inside of the flywheel. new $90.00 flywheel and worked fine ever sense.. FYI

[@Burningquest]

Nice Video. Can you show for what all the levelers on the carburetor are, and how i adjust them the right way? thx

[@ecosystems]

Nice video. I noticed you didn't clean the crud off the motor that was underneath the flywheel. Is it just not worth the time?

[@joshd8654]

nice! i have a briggs 11 hp vertical shaft flathead, cant get it to run it has 85lbs compression spark and fuel. its pull start. when i pull it snaps the cord back hard! i checked the flywheel key and even removed the flywheel to be sure it was ok and its is. any ideas? i did also check that both valves are opening and closing tho i did not check the clearance with my feeler gages

[@natxosailor]

I was annoyed when I tried to use the puller and found the 2 wheel holes were not threaded!!! I am planning to use a M6 tap to solve this. I hope it works!

[@md.shahidulislam8645]

Thanks for nice vedio. I went know same engine & same model ignition problems

[@davidabraham3873]

hey jeremy i have an old 16 hp horizontal Briggs and stratton the long fuel jet i had accidentally snapped at the lower fuel jet holes. will this jet and carb still function

[@MsKeriQQ]

Do you have a video on camsaft removal and checking on a 14.5 hp ohv engine. Was trying to adjust valves and the push rod would not push the valve up or down. First symtom was not cranking. Seemed to have too much compression

[@jonbarfield4915]

did you check the blade adapter ? when they kick back,it may have a cracked blade adpater

[@abstewartful]

Jeremy, where did you buy your wheel puller? I have looked at several outlets but cannot find one specifically like the one used in the video. The puller I have is stout enough but the slots/holes are too wide and do not allow the bolts to align straight into the holes in the flywheel.

[@bdkaka]

I have a 15hp briggs and Stratton OHV that back fires and wont start. Do you think its the flywheel key?

[@Titanykus]

Can you provide a link of model info of the puller you used here? Great video.

[@MarzNet256]

Great how to man. I've got a push mower with 6.5hp B&S engine. It works great-always starts up on first pull. It does however leak a bit of oil onto the deck. I'm guessing maybe loose bolts or bad seal somewhere. Any advice? Thanks

[@gregoryvassar9405]

I have a 14.5 Briggs in a white lawn tractor purging gas from muffler! How do I get carb off to replace float and needle??

[@antoniomarc7174]

Great job…👍👍

[@THEMOWERMEDIC1]

THANKS VM!

[@ronloan4975]

Hi there i really like your youtube channel.

[@watcherwatchmen7785]

Mine didn't have a sheared or even damaged key. Is there a plastic part in the timing on some of the briggs engines?

[@ponyboymidnight]

Another great video, Jeremy!

[@sagitario12ish]

The temperature is remains increasing, and the termostat or chock need to be replaced?

[@rsaved62]

Jeremy, my Briggs and Stratton 210 won't start even though the gas tank is full the line is patent. its almost new but just can't get it to stay running. if I pour a little gas into the carb it will start but then shut down. not sure what to do now.

[@gostrydr]

I'm thinkin' this is the problem with my 2006 mtd yard machines lawn tractor I bought on craigs list last week for $200. It cold starts fine but after it warms up when I engage the deck it bogs out and stalls, then backfires through the carb when I try to restart it. I took the carb off and cleaned it with carb cleaner and ran a wire through all the passages but still the same problem. I haven't messed with the rockers or the ignition module yet. You thinkin' what I'm thinkin' too?

[@Mr_Tecumseh]

Where did you get that handy puller and the tach? I had an engine, Briggs 675 series that had the whole electric start set up deal and when I went to pull the flywheel, I noticed the key was messed up. I got the flywheel of. I just about took that engine apart because when you would try to start it it would blow oil out the carb and pop out the muffler. Sure enough that was the problem. Now I have this Briggs's 675 series motor that had electric start in pieces. Oh well, a spare non electric start engine is going on the mower and now I'm going to just sell the electric start component's. What is the part number for that flywheel key?

[@bestillandknowthatuaregod]

would any fly wheel key fit a briggs & Stratton lawn mower? how do I find out which one to buy? thanks

[@THEMOWERMEDIC1]

Your model #

[@nickwilliams7240]

how do you torque specs and rpm specs for these engines? I took a repair course years ago and when I went through the manuals they never gave me specs

[@Beerpiglet]

You seem to have access to great range of parts in the USA here in Australia we never see pre packaged things like fly wheel keys everything has to be bloody ordered .dont you work at Lakeview mowers these days ?

[@leeb.7188]

I totally screwed up. I tapped the flywheel with a 1/4 20, and apparently screwed down too far, because it went all the way through the flywheel on the left side. So now on one side is is okay, but it is busted through from the bolt on the other side. Do I have to buy a new flywheel? Is there anyway I can fix the hole! Thanks!

[@johngreenfield4146]

I have a Briggs & Statton lawnmower engine that blows black smoke and carbons up the spark plug, can you advise me

[@makingsawdust2129]

Hi Jeremy Was wondering if you have a video that shows how to replace the throttle lever on a Briggs I broke the plastic part that holds the linkage cable

[@pedrojimenezlandero9746]

Maestro a cuanto se calibra las válvulas y la bobina?

[@HLSupply]

Good work Jeremy. Your suspicion was right. Now, no more "poo poo."

[@rtzapper]

Great video

[@billydenham9313]

Take center nut off, then take your hammer and smack the center bolt on top a couple times. If that doesn't pop it off, then put a screw driver up under the flywheel to put upward pressure on the flywheel, then take your hammer and smack that center bolt again! Works with any mower!

[@billydenham9313]

You don't have to hit it that hard! Just a tap will do!

[@joshd8654]

i think its a timing issue the magnet on the flywheel is meeting the ignition coil before the piston reaches top dead center the piston is 3/4 of the way up when the coil is giving spark. just figured this out by removing the head and turning the flywheel

[@joshd8701]

Josh D Weird dude. I got mower issues but something tells me that it's a timing issue due to the magnet on the flywheel meeting the ignition coil before the piston reaches top dead center. Thanks Josh D. But how do youfix it?

[@joshd8654]

Josh D lol weird indeed! i checked this observation about the magnet on the flywheel with another flathead i have it seems to be normal. i did solve my issue though, i had to grind the valves back to spec. they where way off. but on briggs if you do need to set the timing there are two dots that line up inside the motor. search how to set timing on briggs and stratton and you will find videos to help you

[@GaNGsT3RLEAN]

+Josh D A piston never makes it to the top , it should be about 3/4 ... you having timing issues then check your breaker points and ignition coil

[@joshd8701]

It's quit on my twice this summer. Took everything apart including the head and put it back together and somehow it works great. Just needs to be taken apart like lego's and put back together.

[@1KWattmizer]

Hi Jeremy On the mower that you changed the flywheel key on, does the primer bulb have a tiny hole in the center of that red plunger ?? Had some maintenance work done on my husquarna 65021RS recently. A new primer bulb without a hole in it was installed. The old bulb did contain an "air hole" The engine is a Briggs and Stratton. The mower is nearly ten years young. Mower runs well once it starts up. Either 5 tugs on the pull cord or...a spritz of carb spray cleaner into the throat, gets it to roar. Strange that it doesnt want to start with the second pull anymore. Plug, Filter and Fuel are good. Gas cap is vented and oil level is correct. Thank you for any help you can offer me. John

[@GaNGsT3RLEAN]

+john vincaldi check breaker points

[@Schadenfrueda]

I broke one of the wings on my flywheel off. What is that going to do to my mowers performance?

[@perrywmbelll]

Hey Jeremy. Got everything off, removed the flywheel and the key doesn't look damaged at all. Putting it back together, it is difficult to pull. Could it be a spark plug issue?

[@fred306801]

+Perry Bell "removed the flywheel and the key doesn't look damaged at all." The one in the video was easy to see. It was pretty much sheered off. If one of those keys gets as much as the thickness of a peace of paper off it can make it hard to start , back fire , snatch the cord out of your hand. Or not run at all. IF I tare one down that far I will put in a new key. It is only a $1.00. And that is a lot of work for someone to do for being cheap. While you got every thing apart clean the magnets on the flywheel and the magneto "coil " Just brush off with a wire brush or sand paper. Put the flywheel back on regap the magneto. ", it is difficult to pull. " I suppose your talking about the rope. That could be many things. Most likely the break. That is the bar that you let go of when you want the mower to turn off, stop. Sometime those cables stretch or rust in to. Sometime they will move but not enough. That bar does two things. It has a break that stops the engine . And a wire that grounds out the engine, a kill wire. BUT since you had the top cover off and pulled the flywheel . Once you put it back together did you check to see if the flywheel could spin free ? Do you hear a scrapping sound ? IF so you have to regap the magneto. "coil" There is a lot of videos on here. You will need an old business card.

[@leeb.7188]

+William Wynn How do you know if the cable is stretched out too much to release the brake, and how do you fix it? I'm having the same problem as +Perry Bell; I pull the lawnmower starter rope and it only comes out about six inches and then stops. I watched this video to learn how to change the flywheel key, but I'm wondering now if maybe it's the brake not releasing enough, and how would I repair that? Thanks for any advice!

[@fred306801]

When you squeeze the handle that cable pulls the break away from the flywheel. So the engine will spin. To check pull the spark plug out. Have someone hold the handle / break. and try and spin the engine over by hand. IF it spins free it is Not the break. When you say " it only comes out 6 inch and stops. Are you talking the play in the rope ? In other words you pull the slack out of the rope.and then it stop's. IF so that could be the cable not releasing the break. Follow the break cable down to the engine. Have someone squeeze the handle. Notice the direction the lever moves. When the handle is squeezed. What you want to do is move that lever in the same direction just a little. You can use a big set of pliers or a screw drive. USE caution and be careful. Have someone pull the cord. IF it spins free then you know the cable is bad. Sometimes you can tie a knot in the cable. But if you do this it can make the handle hard to squeeze. Just be careful as to where you tie the knot. Not to close to the lever and Not to close to the cable so it can slide into. Depending on how bad the cable is you may have to replace. Sometime when you tie a knot into one they will break. OR IT could be this IF your spinning the engine over and you only have 6 inch of pull then your rope is either tangled up somehow or to short. Hope this helps.

[@Eeropolvasti]

What was the last thing in this video, you were measuring/adjusting??? RPM?? How much it should be, full power?? Thanks, youtheman =)

[@motorsandmore990]

He was using a digital tachometer to measure the rpm, the correct rpm for a small push mower is around 3000 rpm, but it may vary depending on the size of the engine.

[@daleprice8161]

What is the model number on your mower and that puller you used

[@leeb.7188]

So let my bad experience (below) be a caution to others, if you're going to use a tap, be very careful you don't turn it too far. I thought I was going very slowly and carefully, and I didn't push it too far, but I guess the flywheel is more delicate than I thought!!

[@mikelu53]

Keys are now $10 each, I miss the old days

[@leeb.7188]

What about JB Weld? Would that work?

[@efernandezv]

amazing youtube class.........thk jeremy!!

[@ponyboymidnight]

In my area of South Carolina, you usually are SOL if you need anything except the air filters or spark plugs for your mowers or other power equip. Places just will not stock any parts for the DIY guys & gals. They will sell you a lawn mower sure....just don't expect to get any parts for it. That my friends...SUCKS!

[@JOEZEP54]

Good video. Also good idea on video. Let me know if I can be of any help.

[@sibalogh]

My neighbour has a "Mums: Ja #198544#" lawnmower. I guess it was hardly used coz the bearings, the cylinder and the rings are all OK except the exhaust valve came loose. As it turned out its guide, that looks like an insert, crumbled to several bits.Poor old b...d is very disappointed and I'm trying to help him but no idea. Any suggestion?

[@1988MowerMan]

I would like to know what the tool you have to see the rpm and where you can get one. I am a landscaper and i also fix small engines. I usually set the rpm by listening to the engine speed.

[@connorkenney9222]

What would you do if a 40 turn in on the tractor motor blew up again I work for is to work for said that his throat or motor blew up and it was basically junk is it fixable or what I have to go get a new motor because I just want to find out because I don't want to videos and I can't figure out where when I would have to do

[@reazmohammed9686]

Thanks for the info

[@tonypagan8852]

Im just starting out and wanted to know how much you would charge a coustomer for that job?

[@THEMOWERMEDIC1]

65 per billable hour

[@1978strong]

After replacing flywheel key & also new carburetor why would it still backfire ?? Please respond having a little trouble getting it back running

[@wormer66]

+sanders journet i would think at that point it would either be a timing issue or gap spacing on the ignition module from the fly wheel....

[@1978strong]

thanks tried timming y first timing job didn't get it figured out but will try again in the spring please send any tips for me you have thanks

[@northeast13eric]

hey bud, in the case that the sheared key is on there good what do you suggest? I got the steering wheel puller on there, holes tapped to 1/4 20 and it pulled the thread out of one of the holes whille trying to remove it.

[@worstedcdogg]

get a nut on the underside.

[@Ducktruckful]

Hi I have a new Briggs 6.75 peak Tq, engine that kick back like a flywheel key. pulled flywheel to check key and there is no key or keyway on this flywheel? what is up?

[@ponyboymidnight]

Jeremy...I got a Honda HRT 216 S3DA-K2. The Drive belt broke. It is not listed in my shop manuals. My mower tranny is the kind with a "S" shaped rod which sticks vertically out of the tranny box. I am waiting on a 36.3 inch belt, hoping it will be the right one. Grass continues to grow in SC. Any help would be really appre, since all of the parts places around here only want to sell mowers not parts! They wouldn't know a lawn mower if it fell on them!

[@trabbipaul]

Hi me Paul from Germany. And i hope u can help me on a Springproblem on a used Generator with an 8hp Briggs/Stratton Engine. I clean him with a Brush and now a little Spring is not on her original Place . Excuse my english. Sincerelly Paul.

[@09hoseclamp]

i see you used channel locks to hold the flywheel. can you instead use the old "rope in the cylinder" trick on a 4-stroke (with valves, vs 2-cycle engine) to keep the piston from moving to make your final torque, or will this potentially damage valves? i'm trying to "properly" torque the PTO clutch bolt onto the crank shaft of horizontal Kohler Command engine on a shaft-drive Cub but the engine wants to rotate, and impact isn't precise.

[@THEMOWERMEDIC1]

THANKS SIR!

[@spydergto1]

Hello ! i have / was gifted a troy built 21" 725 ex lawnmower, I detest the new throw away mentality and would like to try to diagnose my issue. could you possible help ? my mower will run , but it runs really roughly. i have checked for spark, it has spark. i have taken the carb off and cleaned that and the tank, it had water in the bottom of the float bowl last time, not sure where that came from. i also cleaned the tank and changed the gas. the lawn mower runs but runs roughly. when i run it without the exhaust , yes its loud as heck but it seems to run better, with no exhaust and or air filter either. i figure next free time i get im going to run a compression test on it (will have to buy that) and maybe a new carb. I just don't want to waste the money on the parts cannon if all else fails and have to buy a new lawn mower after having bought those parts. thanks in advance for the information.

[@garybratcher4629]

I have an question, I have an 15.5 HP Brigg's motor, and their is oil coming out the [CARB] while it is running the oil seem to be coming from the air tube, that runs from the base of the carb and the side of the motor, where their is an hole in the side the engine block? THANK FOR AN HELP

[@Smalltechguy]

***** Have you received an answer to your question yet? If not do you have fuel inside the crankcase as well???

[@estrelladelnorte1308]

whats the name of the tool you used to measured the rpms?

[@EricM81]

What is the model number of that Briggs and Stratton Engine?

[@brianmott728]

I have a lawnmower with a Briggs and Stratton overhead valve engine but sometimes the engine will start and most of the time it won't start. I cleaned the carburetor but the groove in the flywheel is slightly off from the groove in the crankshaft. Do you think the flywheel key is broken or cracked?

[@coleyroberts2785]

Brian Mott Street an

[@mtcruse]

Thanks for not using some steel stock in place of the proper flywheel key! Hope you checked the blade as well...