Broke the plastic gear inside

There are a few potential causes for the starter cord snapping back and pulling out of your hand on a Briggs 10 horsepower engine:

1. Weak starter spring: The starter spring may be weak or broken, causing the cord to snap back with more force.
2. Worn starter pulley: The starter pulley may be worn or damaged, causing the cord to slip or bind when pulling it.
3. Worn starter cord: The starter cord itself may be worn or damaged, causing it to snap back with more force.
4. Clogged carburetor: A clogged carburetor can cause the engine to run poorly, making it harder to start and causing the starter cord to snap back with more force.

To fix the issue, you can try replacing the starter spring, starter pulley, or starter cord as needed. You can also try cleaning the carburetor to see if this helps. If the problem persists, it is recommended to have a mechanic or small engine repair technician take a look at the engine to diagnose and repair the issue.

Maybe the starter needs to be shimmed or adjusted so it aligns with the flywheel, or there are teeth missing on the flywheel. The Bendix is supposed to have the gear slide up a shaft and connect with the flywheel. Maybe it is bound or doesn't let the gear slide freely.

Had this happen to me. The problem turned out to be a mouse nest inside the gaps around the flywheel(?) assembly that is behind the starter pull cord.

I pulled off the starter and saw some mouse crud. I cleared that out and reassembled. Pulled the cord again and heard clunk, snap, and breaking pieces bouncing around. Everything was stuck again.

Disassembled again to see some of the plastic blades of the fan snapped and there was a lot more mouse nest jammed in. Spent 2 hours digging out what must have been at least a basketball sized cloud of mouse nest. I had to dig, spin a little by hand, keep digging.

Eventually I got it all out and the engine fired up nicely.

It seems this design a a lot of wide open spaces that suit mice nicely. Combine that with years of storage with no use and you get an epic mouse nest.

bad timing gear or broke dist gear, or broke cam gear,pull dis out and check it first, then go for timing gear!!!

Ok, the spring will more than likely unravel when you remove the pull cord cover/assembly. There is notch in the spool for winding the rope around it. So make sure the spring is wound enough to fit it in the housing. Then take the rope, already knotted and in the spool. Turn the spool in the direction that tightens the spring.Push down on spool and allow spring to retract the rope. (Don't forget to tie the knot in the rope handle before placing on mower). Then lightly clamp in vise or visegrip, or channel lock pliers. I like to use visegrips on one side, and channel locks on the other. Place over the square flywheel nut,release channelock pliers, hold with fingers tightly so the spring does not unravel. Then release visegrips and hold with other free hand, Place over flywheel nut and slide down. Re-attach with screw previously removed. Your done. Don't forget to tie the knot in the rope handle before placing on mower.

Same problem here.After snapping a couple fins off the flywheel trying to lock it with a screwdriver, I had an idea that worked quite well.I used an oil filter wrench (designed like pliers) Item #36778 at harbor freight.The thin design held the flywheel well (very tight fit,had to force past the plastic housing) while I used a socket and power handle.Worked for me and used it when torquing the crankshaft extension nut tight again.

this can be caused by sevral things inside the pull cord hub assembly. examples: Dirty inside & needs taken apart & cleaned. something logged inside, plastic spool tabs broke, spring/s broke, levers broke or any of these items could just be to worn. replacement parts should be available.

I had the same problem. I had to take it apart and rewind it manually. To do this:
Step 1:
There are 4-bolts to remove on the orange plastic section the screw into the motor housing (one of them is hidden inside the orange plastic housing, you'll see an opening for it). There are also 3 screws in the black plastic exhaust housing that screw into the orange plastic housing, find those and remove.

Step 2:
Carefully remove the engine from the plastic housing. I didn't disconnect the throttle cable or the electric wires (points) just kind of worked around them.

Step 3:
The mechanism is kind of crappy. There are two black pieces with a spring in the middle, and a metal disc on the bottom with a ribbon coil on the underside of it. The top plastic piece is what turns the flywheel when you pull the cord. The spring in between connects the two plastic piece. This is probably what popped out. There is a piece sticking up on one end, which inserts into the hole in the top black plastic piece. If you remove the little guardrail things you can probably remove just that piece. KEEP TENSIONS ON THE PULL CORD. Once you remove that top black piece, it should start to recoil.

Step 4:
If it did recoil, put the spring back in the top plastic piece, and then put the plastic/spring combo back into the the bottom plastic piece, there is a little groove for the bottom of the spring to slide into. Then put the little guardrail screws back on. Make sure the big metal wire thing hasn't slipped down into the shaft of the weed whacker. That needs to go back into the motor, as it is what gets spun and in turn spins the strings. As you start to put the motor back in, you may have to pull on the pull cord a few times to get the flywheel and plastic piece to line up. Once you hear the motor start to catch, then you should be able to wiggle it back into place and put back all of the screws. Then give it a shot. If it pulls out again, you may have to drill a new hole into the top black plastic piece for that spring to slide into (this is the crappy design part).

Step 5:
If the pull cord didn't retract, you need to remove the other two pieces (lower black plastic piece and metal disc with ribbon). The metal ribbon has a nub on the outside that hooks onto a plastic piece in the bottom of the orange plastic housing. You'll need to wind it around once or twice to "charge" the ribbon, then wind the string back on the black plastic piece. The black piece should slide into the center of the metal disc and catch the inside of the ribbon. Once you get these two together, again, make sure the metal ribbon piece is wound once past normal and then you have to slide both parts together down into the housing catching the metal ribbon loop over the orange plastic nub. It's tricky, it took me a few tries. Once you get that you can try and test the pull cord, you'll see it pull out and feel it retract due to that metal ribbon. Then go back and do step 4, where you put the upper black plastic piece with spring back into place and replace the little metal guardrails.

This whole thing took a few tries, and the pull cord still gets stuck out. It's a major pain to say the least, but after the 5th time fixing it, you'll be a real pro.

I had the same problem with my 18 inch Ryobi saw. The problem is the tabs that engage the recoil to the flywheel are of poor quality steel and they bend out of position. The end result is when you pull tyhe rope it just jumps and wont start. Eaven the new parts do the same thing. Simple soultion is remove the recoil starter four screws require a torx bit or a flat screwdriver. after your remove the recoil starter using a pair of pliers bend the two tabs upwards untill they are not quite straight up (about a 80 degree angle be carefull not ot brake the tab off) once you have done this remove the center nut that holds the flywheel on. the silver pins that hold the tabs in position need to be punched out but remember how they go back by doing only one at a time and remember how the spring is installed. Turn the flywheel over and using a punch and hammer remove the pins. Put the tabs in a vise to hold them sucerly clean the steel as best you can on the inside of the bend. Fill the bend with brazing rod or coat hanger if you haven't got any brazing rod avilable. You don't have to com;leatly fill the bend but put enough in there to suport the tabas so they can't bend agin. Reassemble the saw and you're done. Mine works great now, better than new. This problem isn't limited to recon saws only, mine is a new saw and I still had the problem. Good luck herbdogs

these usually are threaded counter clockwise need a pair of channel locks to hold the flywheel then with the other hand crack nut open