biggtTex

I HAVE A BRIGGS 14 HP MOWER TURNS OVER GREAT, BUT WANT HIT AT ALL ANY IDEAS, IS THERE ANY WAY U CAN CHECK Magneto Coil ? NO FIRE TO SPARK PLUG

newnewbie

Sure, you can troble shoot the problem.
I would reccomend a visit to you local libraries referance section for a good engine book..
heres one thing i found that wasn't in the book.if the flywheel woodruff key is even the teeny tinyest not even visible bit bent, the motor Will Not Fire.
good luck and keep us posted

BUDFAN8

you may also want to check for rust on the fly wheel. there is a magnetic part on it that has to be clean to work properly.

newnewbie is also correct if the keyway is sheered or bent it causes it to be out of time. if everything looks good then it will probley be your magneto coil. and if there is a way of checking it i havent heard of it but a local small engine shop may know how.

qldit

Good Morning All, yes I have seen a few of those flywheel keys sheared, they were originally diecast metal, but I usually replace them with steel ones.
That failure gives the symptom you described.
Apart from a coil or electrical problem which is rare.

Cheers, qldit.

K-B

The way to properly diagnose a spark problem is by isolation. Start with the spark plug, have you tried replacing it? If that doesn't fix it, you need to eliminate the safety switches. Modern lawn tractors have a transmission clutch "neutral" switch, a blade clutch switch, seat switch, low oil switch... What you need to do is disconnect the ground "kill" wire that plugs into the coil. Many times there is a connection that can be unplugged about a foot from where the wire comes out of the coil. If there is none, on most coils that ground wire can be unplugged right at the coil. You'll have to remove the engine shroud to get to it. If that doesn't give a spark, you can be just about sure that the coil is bad. They do fail from time to time.

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ozplanet

99% of the time it is the magneto. Set the gap for the magneto on the fly wheel. The easiest way is go get a match book cover loosen the bolts to the magneto put the match book cover between the fly wheel and the magneto, push the magneto down on the match book cover tighten the bolts. Do not make it soo tight that you cannot get the match book cover out just snug.

This is of course after you check for fuel. Pull out the spark plug and see if it fludded. If soo spray some starting fluid down the plug hole leave the plug out and krank the engine a few time to dry things up.

trailrider894

listen i think that it is the magneto to but if the motor is cheap just ditch it i have had this happpen to many time's on my go-kart motor's.

strate8

It would be best if you use plain ol writing paper for adjusting the mag clearance. It's close to .010 " which is what it Should be ! Matchbook covers are good for the points on a VW bug,which is .030". A close adjustment will result in a hotter spark. Cut a strip of the paper about an inch wide and long enough to cover the mag. I bring the magnets on the flywheel around til it's over the mag,holding the paper tight. Now,do the 'tighten up',like James Brown, turn the flywheel and the paper falls out.

strate8

Two things ! On my first post,I should've told you to cut the paper 2" wide and fold it in half. That'll give you the .010". Rust on the flywheel magnets doesn't hurt nothing !

strate8

Ya gotta be careful who you listen to ! Here are a few corrections ! If the woodruff key is slightly bent,it still should do something,like pop or run erratically. The manufacturer supplies woodruff keys that WILL shear off when under a sudden load,like hitting a rock or stump. If you change to a stronger one,you're putting a load on the crank shaft. That's why they're made of die cast,so they WILL shear off ! Like a shear pin on a outboard motor. Then there's the rust on the flywheel magnet ! Rust won't affect the magnetism,will it ? NO ! Clean it if ya want ! The guy who said "ditch it" must have some real good engines lying around !

RIGHTE0US

are you sitting on the seat when checking for spark?. There's a trigger under the seat that shuts the spark off in case the operator falls off the mower.