28 thoughts on “Fixing the starting problem on the Briggs and Stratton 21hp engine

  1. Sanding has nothing to do with it. The fact the coil was a nautical mile away from the flywheel/magnet was probably 95% of your problem.

  2. I want to thank you for producing this video. I was having the same problem. If I got it started it ran strong but getting it started was a problem. I removed the rust from the flywheel and it started right away and continues to start with no issues. Thanks again.

  3. You need to go back to your day job at wal-mart greeting customers and cleaning the toilets. cleaning the rust on the Flywheel was not the issue and you are not worth me teaching you the issue. also do us all a favor and purge your shitty vid because your a moron!

  4. Why am I having to spray wd-40 into the flywheel area for my kawasaki 20hp lawn mower engine to start? It was left out in the rain a few times and mine is rusted like this one is. But I can spray a little into there and she will crank and run fine.
    What's the fix? Did sanding that rust off really work? Thanks!

  5. I have the same exact problem on the same exact mower a ys4500 with a 21 hp briggs I'l try this I hope it'll work, it cranks and cranks and eventually starts after varying the throttle unlike a 15hp briggs ohv that I have that starts almost immediately

  6. I have a 2013 Troy built. I have replaced the starter,coil spark plug ,battery, and ignition coil. Still won't even turn over,I checked and motor is not froze up. Any suggestions?

  7. I adjusted valves like video my 21h single valve brigs still will not go by compression stroke battery's good starter good runs good if you turn fly wheel past compression an then start with key runs great

  8. I have the same mower. it is 12 or 14 years old. still runs perfect. it only had normal things fixed/ oil filter,fuel filter,sparkplug,air filther, but never a engine rebuild or carbkit. nothing major. and a 17 year old toro with a tecumpseh engine. same as the craftsman nothing ever replaced. just normal things. still runs great.

  9. The coil or magnetron gap is easily figured out by placing a business card in-between it and the flywheel. Tighten the magnetron bolts and slide out the business card. You may also want to sand down the edge of the magnetron which faces the flywheel. I always keep a business card in my tool box just for this purpose.

  10. I have a craftsman lts1500 Briggs &Stratton 17.5 hp. I've clean just about everything possible but the mower will only run on high. The throttle has to be half way to start. Have you or anyone self run into this problem?

  11. Good gap for your coil is close as can be without touching flywheel. As another said rust does not matter. An old timer told me 30 years ago use a brown paper bag. Of course that was when they were plentiful.

  12. there's only one spot on the flywheel that's a magnet, it's the part that has that counter sunk screw that you have lined up with the coil @ 3:39 and I'd say that the way the coil was misaligned was most likely the problem…rust really isn't an issues on the flywheels unless it cause the coil gap to close up…

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