This guy knows his shit! I thought this lawnmower I’ve been working on was out of time because it was starting hard and the rope would snap back on me about every 3-4 pulls. I’m glad I watched this guy so I can get this lawnmower running right and out of my garage and back to the owner! I just got done putting the new keyway in this craftsman lawnmower and it started on the first pull and ran just beautiful! Thanks alot Bruce! You’re alright man!
Just put the new keyway in and she started on the first pull and ran just beautiful! Thanks alot Bruce! You will be my “go to guy” the next time I’m struggling to fix a small engine.
Bruce, I can't thank you enough for this video. My rototiller just about broke my arm last time I tried to start it. Now I can't wait to take it apart and look for the broken key! You saved me-THANK YOU!!!
Bruce, you just saved me from another wasted weekend of mower madness. Couldn't figure out what was going on until I found your tutorial by searching for "snaps back". Fifteen minutes, an impact drill, crowbar, and a $1.50 flywheel key is all it took. And it started on the first pull! I'm back in business. Molsons for everyone!
I just serviced our mower. That is good info Bruce thanks for posting. Have some catching up to do been working in Zurich so doing 3 or 4 hours driving a day. But I got 4 days at home now ;-) Good to have no parts left lol. Sounds sweet now sir. Dave
Thank you, Mr. Pender. Using your tip concerning flywheel removal, I was able to rob one mower to fix another. Also, using what I've learned from you, doublewide6, Steve's Small Engine Saloon, and Foxboss9, I have landed 2 part time jobs doing small engine repair and tuning. I've learned from others, but yours, Steve's, doublewide6, and Foxboss9 have been the best. Consistent, on-track/on-topic, well-illustrated, clearly explained without condescension, and no distracting soundtrack.
Very informative, thank you. I took lawn mower repair classes in high school, and repaired a couple like this, and sanded parts, And repaired strings, it was nice to have a running motor at the end of the repair, Its has been lots of years since I did that, it was good to watch this video, a good refresher!
Hey Bruce!! Thanks for the help!! I'm going to pull it apart today!! I'm a rookie at this kind of repair, so wish me luck!! Great Video!! Thanks again!! RS
Hi Bruce What a great tutor you are . Thanks for the tips . So many people today are more likely to throw away rather than take to the time to lean and repair. Well done mate.
Mr. Pender after getting wacked by the pull cord handle ... a BIG ouch ... as you mentioned is rather dangerous ... your repair know how has given me the courage to attempt the repair myself ... thanks ... keep up the fine job Dude !!!!!
Lol I was fixing an old tecumseh mower for someone and I remember this was the issue. I found that out when my arm just about got ripped off! Came across this video and it made me laugh. Thanks.
One of the easiest going people on RU-vid, knows his stuff and has helped me solve numerous problems in my mower repair work( I was a trucker for 44 years, some health issues and early retirement so I took to mower repair as a hobby and it evolved to a little side hustle😜) . Like I said Bruce has helped me out through his videos numerous times, for which I am in his debt. 👍😜🇮🇪
Good video and good repair Bruce. I ripped you pretty bad on a riding mower deck rebuild but I have nothing but good things to say about this repair. I was given a mower with the same issue a few yrs. ago. I told the lady that it was more than likely just a flywheel key and I could fix it for next to nothing but she had already purchased a new mower and said "take it" I repaired it and sold it to an older gentleman very cheap.
Thank you Bruce, very neat shop and super pleasant to watch your work. My 25 hp Nissan outboard it breaking my hand of snaps back hard. I ll check the key if broken.
I had to laugh at the end when you brought the oil burner outside but kept the exhaust blowing into your shop. Other than that, it was a great video. Keep up the good work. Subscribed.
Thank you Mr. Pender! Same here, you saved me tossing a perfectly good mower and paying hundreds for a new one. Old Toro with Tecumseh 6.5. Slammed the blade into an iron hammock stand. Tried to start, got the severe kickback. Google turned up your video. All worked out exactly as you described. I was a little unsure how to get the flywheel off, feared I would break the cast aluminum wheel. I wound up rapping it with a rubber mallet and it popped loose. I had to tap a little nail in behind the broken key piece to knock it out of the shaft. Only other problem was having to wait 10 days for the local mower shop to get the flywheel key in. Cost $2.22. Upon repair as you instructed, the mower started right up as usual. So thanks again for taking the time to make your video!
Don’t be afraid afraid to apply pressure with a prybar under the fly wheel on top of the keys you don’t have to use a ton of pressure just enough up force and then crack it either with a rubber mallet as you stated you did or put the starter cup key back on top of the fly wheel shaft or crankshaft which ever you prefer to call it run it down flush to the top of the shaft and when you tap it you just need to give it a nice solid tap as he did with the piece of wood on top of his shaft and it should pop right up or you can use a thicker chisel And tap it under but do you have a possibility of Nicking the aluminum casing, Just pray like Mr. panda showed you slide up for a good tap on top of the shaft make sure you’re not mushrooming the top if you have the nut on it protects the top from mushroom if you don’t hit it squarely
Great video! I wasn’t exactly sure why my mower was pulling back and I never would’ve though about the flywheel key! It’s a Toro GTS with the 6.5 HP Tecumseh. And sure enough after I opened it up it was shredded! Popped a new one in and the thing fired right up!
Thanks for this video I was going to get rid of my mower due to kick back was able to fix it starts on the first pull and purrs like a kitten thanks to your video!!
Worked like a charm! Separated the flywheel as shown in the video. Replaced the key, cleaned the mower up a bit, new oil, plug , gas & a shot of WD-40 into the cylinder & gas tank. Couple of pulls later, mower ran like new! OBTW - Tecumseh motor parts are becoming scarce, will have to buy a new air filter on-line, but was able to locate a flywheel key locally... waz
Learn something every time I watch your posts. Thanks for taking the time to post such interesting cases. Where did you get such a nice and helpful hoist/lift?
Bruce, thank you for a most brilliant tutorial on the snap back problem. Your photography, clear concise directions, and a good bit of your humor make it a real gift to all of us in youtube land. I have a 1960's sears lightning chainsaw that snaps back.The problem is most noticable after i choke the engine to start it. I will first check the flywheel key. Can the problem be that its getting to much fuel, cause the carburetor needs work? Thanks again and god bless. Bruce the swimmer New Rochelle N.Y.
Hey Bruce. Had a a hard time getting the flywheel off as I didn't have a puller. The key seemed to be a permanent part of the shaft and appeared not to be out of place. I cleaned everything and removed some rust from the contacts. The mower started on the second pull with no kick back. I really don't know what I fixed but I guess the cleaning did it. Thanks again for your help. RS
I injured my arm twice badly while starting lawn mower after replacing all gaskets, spark module and carburetor. wondered why this is happening, time to check this key out. Thanks for the video
Hi Bruce. Another issue can be the rotor base plate if that’s what is fitted. ( common in Australia ) . If the base plate isn’t torqued on adequately, sometime 60 NM, it may slip. The base rotor In some motors IS the flywheel in the truest sense of the word. It’s stores energy via angular momentum. ( remember is spins at 30 times per second at 1800 rpm! ) anyway , a slipping baseplate , or no base plate , will mean the motor is really difficult to turn over. If the motor runs it will back fire etc. I know all this from bitter experience with my tecumseh ULT50. Ps love your videos! Keep up the good work
Well I use a impact wrench so mine will never slip. I tighten them to much. I manually check to see if the piston is almost at TDC when the coil is near the magnets. (manual advance timing)
Hey Bruce. It is a Tecumseh 6.5 hp Yard works!, Just started it again and is running like a Top. No kickback, but I'm still cautious when I pull that rope!! Thanks. RS
Thank you Bruce! I don't know much about motors, and mechanical stuff, so you explaining and show your tips is greatly appreciated. This was exactly the issue with my mower, and I managed to fix it by my self after I saw your video. Again thank you Mr Handyman ; )
Hey Bruce, thanks for explaining this issue. My old Quantum 4hp (bought it at K-Mart!) has been doing the cord snap for a few seasons and it seems to have got a little worse over time. Now that my boys are using the mower I can see that it's a little dangerous. Time to fix it!
Bruce Pender Hey thanks a bunch for taking the time to show this stuff. My flywheel took a few whacks on the wood block, then popped right off. This fix worked great, no snap-back & more power! Parts under $5 for key & carb gasket. Kids start with one pull. You're saving me $$$ & headaches!
Bruce thanks for the video I have exactly the same lawnmower with same problem. But, I can’t get it started after changing the pin. It looks like I’m not getting any sparks. Do have any suggestions
I just learned something here watching this. The key must match the slot. I had my 7hp mower doing this too and I had it apart down to the flywheel but I didn't know what to look for, now I do. I just took my mower to a guy in the next town over from me because he fixes small engines. I wish I didn't now but he is reasonable. If I had known this I would have jumped on amazon for a flywheel key set. Not sure which one my mower takes or are they standard?
Good info. I tried this but my key was fine. Ended up starting it with my drill while the pull cord was off. Fired up after a couple of attempts. Guess it just sat up too long.
Great video, after years of repairing small engines I would only add one critique. Before removing the top end you should disconnect the spark and pull the rope and observe the blade and rotation of the crankshaft for loose bade or warped shaft and then proceed to the flywheel key
You are right. I don't film everything i see. As every video would be 2 hours long. But you are right, Thank yo, that is how I check for bent cranks as well.
You do nice work. I pop off the flywheel the same way with a hammer, but I think if I was doing an instructional video, I would go by the book and use a puller so that way if some idiot busts up their engine, they won't blame me for it. Otherwise, thanks for taking the time out for making the videos. :)
What is actually moving as far as the crank or engine when you rap it with the block as you pop the flywheel off. My lawn mower is running really bad, and almost tore my wrist off after kicking back. It tore the rope in half again.. I thought it may be the lightened blade after years of sharpening the edge maybe being too light. Thanks for pointing the real culprit. Over a time i must have stopped the blade on something maybe 4 times. Thanks for the video. Frank
Well there is something igniting the fuel when the piston is before top dead centre. It could be a leaking intake valve. You can take the valve inspection plate of and check to see if you have enough valve clearance on the valves. 6:45 into this video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-coZfgnII-hc.html
yo, dude, I put a 173 Predator as as replacement for an old engine. Today, I thought I would split some wood on the log splitter... Two pulls later, the whiplash from the starter rope, I thought I had broken two fingers!!!!!!!! After seeing your informative video, it is time to see if that is the problem...thanks, eagle-san in colorado
You have a real neat and tidy shop there Bruce , wish my garage was so tidy , is that a record #6 vise that is bolted to the work shop bench ? If so thats a real nice vise . keep up the good work.
On old engines that have points, shearing the key causes the engine to be totally dead because the point timing is correct, but the magnet timing is early, leading to no spark.
good video, explains why my engine is jerking my hand off. suggestion - move your lawnmower stand (it has wheels) closer to your work bench and tools to save some steps back and forth.
@Bruce Pender i have a predator engine it backfires when pulled and turns on but revs really really high the governor was taken out any thoughts on what it could be?
Bruce I have a Sears tiller takes your arm off pulling on the rope .I checked the key way and it is good the fly well is steel about 10 or 12 years old could the valves need adjusting and can you a just them. Sam thanks
What type of motor is it. If it is a flathead (valves in the block you can remove the head and shave a bit off the valve) If is overhead valve (aluminium valve cover) You can adjust the valves easily.
I understand this is a common problem with tecumseh motors. Is it also common on Honda's? I just had one rip the handle right out of my hand several times. It would run and sputter a few times when it did start. I also don't have a blade attached. Will this have a significant impact on the engine firing too early?
This link is for a Briggs The video was a Tecumseh. Similar but different. www.amazon.com/Briggs-Stratton-Flywheel-Key-5002K/dp/B00004RB14/ref=sr_1_1?keywords=Briggs+%26+Stratton+Flywheel+Key+5002K&qid=1556038217&s=gateway&sr=8-1
I've got a Cub Cadet 173 push mower spray starting fluid to to start it it jerks the Rope out of your hand real bad and it won't stay running I'm going to have to pull the flywheel off and see if the keys broke appreciate the video
Are all flywheel keys basically the same in all mowers?? I have the same problem with my 6.5 hp Yard-Works mower!! Almost broke my hand the other day!! Thanks RS
+Ron Scott No Basically Briggs and Stratton are different than the Tecumseh. If it is a Tecumseh the flywheel keys are not "square". The Briggs are a rectangle shape. You should be able to see the make of the motor by looking closely at the engine. The disassembly is almost identical for both.
I would have a real close look at the key. Even though they look fine, When you remove them there may is just a deformation on it----------- this can cause the kickback.
Hey Bruce, I checked for the fly wheel key and its intact on my mower. So what else could be causing the problem with the rope snapping back? Thank you.
Hi Bruce, I was given a Weed eater lawn mower with a 5 hp Briggs engine. Its the newer style Briggs you see on pressure washer and a few different lawnmowers. It was given to me after it hit something because off the terrible kickback. First thing I checked was the flywheel key. It looked ok but I changed it anyway. Put it back together and it still has bed kickback. Any ideas on what else to check?
Bruce is there another possible reason why it kickback even when flywheel and key are not sheared or damaged thanks ps it was running before started good thanks
Yep pulled a 3 year old snow blower out of a neighbors trash because it caught fire backfiring. Looked up a solution on the tube adjusted the valves and replaced the melted plastic parts! Following winter I was using his blower and he kept looking as he passed in his car LOL
Hi Bruce, Thank you for another FANTASTIC video. If the woodruff key isn't tapered, and isn't square, how does one determine the orientation of the offset (when the keys are offset) ??? [for the other viewers, many woodruff keys are square, (looking from the top down, but long) and it doesn't matter] under the conditions which you have presented, the key is offset, and sometimes it ISN'T tapered. Is there any 'trick' or advice that would determine the orientation of the key ? Thank you Bruce, for all of you FANTASTIC information. You are a great bunch of knowledge.
I just watched Donyboy73 do one of these and the key is straight. I have done them too but this one just came to mind. here ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-FwBMBRk852M.html
And if it's not the key then what else could it be? I have the 6.75 Tecumseh engine which is basically the same, the carb was flooding and I can smell gas in the oil but the oil is not diluted the key is good I'm stumped at this point. I did manage to get it started then it would stall so I was looking to make sure the governor wasn't stuck then found that it wasn't even connected to the carb, somebody had just put a bent piece of wire on it and of course it wasn't attached properly, when I sort of attached it I got it started again but even revving it up the engine wasn't running at the proper rpms, would the governor not being at the correct setting cause the cord to snap back, I've worked on many small engines but this one I can't figure out.
Yes they do. My impact is a weak one so I just tighten them up. Yes everything on a mower has a torque value. If it is motor related I use the specs. Thank for the comment You are correct in asking. 450 inch lbs for some up to 600 inch lbs. 37.5 foot lbs for 450 inch lbs
Excuse me I have a problem with my 4500 champion welder generator, engine jerks pull rope but engine starts welds good no missing, the key don't look broken help me
Hi Bruce, I enjoy your videos. I watched the one where the pull rope snaps back . My question is, I have a Troy Bilt pressure washer that is doing the same thing. It feels like it's going to take my arm off. I can understand a mower having a sheared key. It is a B & S engine. I have not taken the cup off to examine it yet. Once I get it started it runs fine. Have you any ideas that you might share with me? Thank you for your time and info.
This can also happen with the overhead valve engines if the valves are out of adjustment. Just take the valve cover off and check the valve lash clearance. I will send you a pdf link in another reply as sometimes links go into the trash file
Thank you for getting back to me so quickly. I received the specs link also. I have a copy of the specs for B & S engines. I have had this pressure washer for several years. I have replaced the pump on it once since I have had it. I am fairly new to the small engine repair thing. After paying out the wazoo a few times,(on different equipment) I decided to try to repair my own equipment. Watching your videos have helped me tremendously. The troy bilt PW is an 875 series 190cc.. After I had thought about it, I remembered that it had done this prior to my looking into it to see why if wasn't running properly. Found out the carburetor was loose. The left side bolt holding the carburetor on was broke off flush to the head. Tried drilling it out and boogered it up. Bought a new head put it on and adjusted the valves per specs, put the carburetor back on and found it was hard to pull (very). Once I got it started it ran good. Am planning on taking it apart and check the keyway and re-adjust the valves if the key is sheared. I did have the piston at TDC when I put it back with the new head. Again, thank you for your time and information.
Bruce Pender Again, I thank you. I re-adjusted the valves, primed it and it took three pulls an it fired up. The first pull, kinda hard, the other 2 were much better.
I wonder if this can be my issue on my ariens snowblower? anyone have any thoughts or comments, bts my pullstring is hard and sometimes snaps back, easy to pull with out the plug and pulled the front cover and no debris
