9hp Tecumseh recoil snapping back, starter gears breaking

brinkkl2000

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  • / 9hp Tecumseh recoil snapping back, starter gears breaking
I know, another one of these threads. Seen a lot of info but never seen anyone post their resolution. As the title suggest the recoil is snapping back when trying to start it. Once running it runs perfect. The engine was rebuilt last year, and I am assuming the cam timing was put back in properly as the engine runs great once it starts. What I have done so far, cleaned carb and verified it isn't leaking past the seat, pulled flywheel and cleaned all the magnets, installed new key, verified keyways on crank and flywheel are in good shape, and put a new spark plug in and decreased the gap slightly. Is there something else that I may be missing?
 

brinkkl2000

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  • / 9hp Tecumseh recoil snapping back, starter gears breaking
Just a thought, for anyone who may be seeing this, could the ignition coil be on backwards?
 

bertsmobile1

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  • / 9hp Tecumseh recoil snapping back, starter gears breaking
yes you are going the wrong way, widen the spark gap to retard the spark and / or widen the air gap on the magneto to also retard the timing.
Snap back when cold is always early firing and that is either too lean a fuel mix or too early timing.
 

brinkkl2000

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  • / 9hp Tecumseh recoil snapping back, starter gears breaking
Well, I widened the air gap, and widened the plug gap and still get a snap back, almost feels worse. Looks like the coil is on the right way. Anything else. Would a faulty ignition coil cause it?
 

brinkkl2000

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  • / 9hp Tecumseh recoil snapping back, starter gears breaking
Hopefully someone will chime in on this yet. I have a photo that shows the position of the flywheel when the piston is tdc. The piston still has about an inch to travel up when the first edge of the magnet is about to pass the first arm on the coil. I believe there is also a screwdriver stuck in to the body of the coil, just to show that the case has separated from the rest of the coil and maybe that is part of the problem? Again I have checked the key way on both the crank and the flywheel and both are perfect, as well as the key itself is new. I do think it is a timing issue, but everything is assembled and together the way it is supposed to be, with the exception of possibly a bad coil.
 

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