Sheared Key?

[JOEX]

This is for a Briggs & Stratton 5hp rototiller motor that isn't getting spark. I replaced the plug and the coil and still nothing.

Someone told me that the key may be sheared, wouldn't it still spark but at the wrong time?

Any other ideas?

[wilkin250r]

If something happened with the flywheel severe enough to break it loose and shear the key, the flywheel may not be moving at all. Have you verified that the flywheel is still intact and moving with the crank?

I've never worked on a Briggs, how is the ignition setup? Do you have any sort of manual, or looked online for ignition troubleshooting?

[JOEX]

The flywheel moves like it should.

I've looked a little about troubleshooting but everyone just wants to sell something:rolleyes:

The coil mounts outside of the flywheel and the curvature of the flywheel matches the curvature of the two 'legs' of the coil which resembles the pic. There is a magnet imbeded in the outer edge of the flywheel that triggers the spark or something like that, highschool was a long time ago:p

[wilkin250r]

I don't think I can help all that much without actually seeing the components in person, or seeing an electrical schematic. If I know the components involved, and how they are connected, I might be able to give you some general guidelines on testing them to see if they are good or not.

How many wires are coming out of the coil? Does it look like it has a separate trigger? Is there any type of electrical component external to the coil?

I had a tamper last year witha briggs motor in it. It kept shearing keys then eventually the motor took a dump. I have no idea we replaced the key like twice.

[redrider05]

is the kill switch working its possible it could be grounding itself out.... n yes if the key is sheared it should still spark...but the last time u used it did it jus stop running or did u stop it and then it quit getting spark?

[JOEX]

Originally posted by redrider05
is the kill switch working its possible it could be grounding itself out.... n yes if the key is sheared it should still spark...but the last time u used it did it jus stop running or did u stop it and then it quit getting spark?
There isn't a kill switch that I know of, it turns off with the throttle/choke lever.

I wasn't the last one to use it, I lent it to someone and when I got it back several months later it wouldn't start so I don't know what happened and i'd rather not talk to that person for other reasons.

There is one wire from the coil that goes into the block, what is that for? I just cut and stripped it to attach the new coil.

[plkmonster2]

That wire grounds your coil. Disconnect it, and it should spark.

[wilkin250r]

Originally posted by plkmonster2
That wire grounds your coil. Disconnect it, and it should spark.

BAD IDEA!

If you do not know exactly what that wire is, and what it does, you don't want to go fiddling with it and disconnecting it. It's very possible that wire provides the ground potential for the entire circuit, and if you disconnect it, you may have an incomplete circuit path (open circuit).

[plkmonster2]

Hey wilkin, I looked again at my 11hp briggs, and the wire that comes out of the coil goes directly to the kill switch.

[wilkin250r]

I doubt he has the exact same coil, since he does not have a kill switch.

[plkmonster2]

Most of the briggs coils are the same. There are only a few slight differences such as the curve to fit the flywheel. If you are still doubting me JOEX, disconnect that wire, after you pull the plug out, and put the wire on it. Ground the plug, and spin the engine over. Oh, and another thing. Take your flywheel off while you are at it. The briggs have a really bad problem with the points sticking open because dirt will collect in them.

[redrider05]

Originally posted by JOEX
There isn't a kill switch that I know of, it turns off with the throttle/choke lever.

I wasn't the last one to use it, I lent it to someone and when I got it back several months later it wouldn't start so I don't know what happened and i'd rather not talk to that person for other reasons.

There is one wire from the coil that goes into the block, what is that for? I just cut and stripped it to attach the new coil.

yes there is a killswitch for those...its connected to the armature on the side of the block right where the throttle cable connects u will see that wire that connects to the coil....u can pull that wire off and pull it and c if it sparks...and if it does right where that wire connects to the armature it could be bent and grounding itself out....something to check out....there isnt much to these lil engines....sheared key,bad,coil,grounded killswitch and ofcourse bad plug is bout the only way for it not to get spark

[redrider05]

i am assuming that is a solid state ignition on that....if its points that will most likely be the problem...plkmonster2 is right the points do stick

[plkmonster2]

It is "solid state". Um, not sure, lol. I don't know exactly what that means, but... most briggs have points, and some have a generator. This charges up the battery. Hey JOEX, what size is your engine. Now that I think of it, there should be 2 wires. One goes to the points and grounds it out. When the circut opens, it sparks. The energy is made from the magnet on the flywheel.

[plkmonster2]

OK, I went through a few more things. I need to know wether or not a wire goes behind the flywheel. I read that briggs has used 2 different systems. If there is a wire going behind the flywheel, you have points. The points could be dirty, or the flywheel key is sheared. The points are closed when the charge is made, and it is just grounded out if the flywheel sparks at the wrong time. If there is no wire going back there, your coil is shot. Also, I have heard that you need to set the correct gap between the flywheel and the coil. One guy said to stick a business card between the two and tighten down. Hey JOEX, it would really help if you could get me a pick of YOUR motor.

[JOEX]

Thanks for all the replies everyone!:)

I haven't had much time to mess with it much lately but I tried disconnecting the 'ground?' wire with no luck. If it has points will they be behind the flywheel? Haven't been able to find my wheel puller so the flywheel is still on:(

Here are a few pics if they help...

[JOEX]

....

[JOEX]

I'm not sure about the kill switch:confused:

[plkmonster2]

Yup, i can see the wire going behind the flywheel. When you take it off, make sure to check that it is in the right position, and clean the points up. Also, make sure to regap them.

[JOEX]

Originally posted by plkmonster2
Yup, i can see the wire going behind the flywheel. When you take it off, make sure to check that it is in the right position, and clean the points up. Also, make sure to regap them.
Thanks :)

When I find my wheel puller do you think the aluminum piece is connected to the flywheel and will it be strong enough to pull the flywheel off? The bolts are kinda small:ermm:

[plkmonster2]

Umm, DO NOT pull on the one way. it can't take much. You take that off, and use a puller. A steering wheel puller shoudl also work. you just bolt it into the flywheel, and twist away. With a loud bang, the flywheel pops off.

[2muchquad]

if your briggs has a "solid state"ignition,then it WONT have points.hence the words solid state,no moving parts.could be your coil:)

[plkmonster2]

that one is not solid state. I believe that the solid state's have 2 parts to the coil. One is black, and one is white-ish yellow.

[redrider05]

to take that fly wheel off take that silver thing for the recoil off and jus put a big flathead screwdriver inbetween the block and the flywheel and start to pry on it and then get a hammer and tap on the end of the crankshaft and that flywheel will jus pop right off....this will work 9 times outta 10.....i go to a tech school for small engnies so if u need any advice jus shoot a pm

[smith_400ex_213]

maybe emery paper your flywheel and get some of the rust off...try the armature gap between the coil and fly wheel adn take the coil somewere and get it tested for spark ....also is ur plug cap good

[JOEX]

Will the thing for the recoil just 'pop' off? I really don't want to break anything, I know that gets expensive:o :p The coil was $40, probably twice what I should have spent:( :ermm:

There's no rust where the magnets are and I used a piece of thin cardboard about the thickness of a matchbook/business card for the coil gap.

What should the spark plug gap be? Maybe i'll get the 'nads to hold the plug wire while pulling the rope:ermm: