No spark from head on ignition. KA100

Went to start the motor for the first time and everything went well but it didn’t start. took the head off the spark plug to check if it was getting a spark and nothing. aligned the magneto and set the distance on it and still nothing. very perplexed on this one.

How’s your coil grounded?

I wanted to reply before I deleted this thread, but I figured it out. I unplugged and replugged all the connections. pulled the spark plug out and reconnected the coil and pushed the coil onto the spark plug better, and it finally fired. must have been a bad connection originally between the coil and plug

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Charles I do have a question. I ran the kart for about 30 seconds. and the engine was sputtering quite a bit. now it is a used engine but the first time i have put gas in through it. is that why it is sputtering and going in and out of throttle? or is it something i need to look into?

Hard to tell without video but it could be air in the fuel line or maybe there is actually some kind of electrical connection issue.

What are your carburetor settings?

i got them completely baseline at 60 minutes. but sadly right before the test drove it the low speed needle broke off. but it was in baseline when it broke. (it was my fault it broke i got careless and it snapped while i was fitting the fuel line)

and i know dumb question but can i superglue that needle on just to test the carb until my new one arrives. i’m not doing any running until then. just checking the motor while the back wheels are off the ground

would the brass handle breaking off render the low end completely useless resulting in the sputtering? because the handle can not compress the spring? i’m sorry i’m asking a lot of questions i’m very perplexed

Need to see a picture, not sure exactly what you mean, I’ve never seen a carb needle break off before.

don’t have a picture but what i circled is exactly what broke. it was a clean cut

Weird. Anyway that shouldn’t affect the carb at all, it just keeps you from easily setting that needle, but if it’s already set at 60 min it should be fine. I would just leave it and order a new needle.

Sputtering is probably fuel or electrical related but hard to diagnose without hearing it run.

What fuel and oil are you running? And at what mix ratio?

i know i probably shouldn’t but i ran 91 non ethanol mixed with red line 2 stroke racing oil at a 16:1 ratio.

any other racing gas is not available anywhere near me and i didn’t want to order a 5 gallon pail of 98

now my plug is not firing. i changed plugs to a brand new one and it still won’t fire

Lots to unpack here:

Is there enough needle left to remove it with vice grips? Make sure you get the correct needle. High and low are very similar but not the same. Superglue is not going to work and epoxy likely won’t either.

As I recall you redid the carb. Are you certain everything was reassembled correctly?

The sputtering is going to be tough to figure out as it could be many things. If the fuel is fresh it likely isn’t the problem. The spark issues may be part of it. How old is this motor since a rebuild? I have a KA that as it wears and loses compression it doesn’t want to start and once it does, there isn’t much power. A quick check…can you turn over the motor with just your fingers? If you can (with the plug installed) you will need at least a top end rebuild.

Did you move the coil?

yes i followed reassembly to a tee on the carb and i only did the gaskets. it is 4 hours brand new no rebuilds. and what do you mean did i move the coil?

i got the plug to spark and fire for about 3 starts. i went to the store and came back and now no sparks.

and what do you mean can i turn the starter with my hands? i can easily spin the ignition magneto rotor counterclockwise if that is what you are referring to

At the top of the compression stroke, there is a build-up of pressure. On a fresh motor or one with good compression, it should be difficult to impossible to make a complete cycle using just your fingers to turn the crank. This is with the spark plug in, as if you are trying to start it, obviously with no plug there is no compression. This isn’t a very scientific method but something to check. A motor is a pump and in particular 2 strokes need pressure to move the fuel charge on each stroke.

As for the coil, on the seat side of the motor, they are adjustable not only for distance from the crank but to also just the timing of the motor, when the spark plug fires. You mentioned you adjusted it in your first post. I assume you meant this
276A) A-61951A IAME KA100 Ignition Stator with Magneto Rotor ...
There is a method to set the timing but it requires some specialized tools and knowledge.

The other thing I would check is the spark plug boot. When you get a new motor you have to join the boot to the spark plug wire. That can fail, maybe a bad connection either at the spark plug or the wire to the spark plug terminal.

i’ve pretty much ruled it down to the spark plug cap, or the ignition coil, which one do you recommend i replace first?