Do you have spark at the correct time?
Have you re-checked the key? Why did you replace the flywheel to begin with?
Think about it PT,
You have been doing this for long enough now
\The magneto coil generates the power for the spark
There is nothing to store that power on most engines so it has to happen just before TDC
So the magnet needs to be just passing the coil then the piston is at TDC for the timing to be good enough to at least get a bang out of it.
Generally the magnet will be just past the trailing leg of the coil.
ANd this is the same for every engine you have worked on except those with some sort of a SAM module or a capacitor.
Have a look at some of the stuff you have around there that works.
The amount the coil passes is different for 2 leg & 3 leg coils but most are around about the same amount in degrees of rotation, type for type .
You can flood an engine with sprays every bit as much as you can with a liquid fuel
Next time you find yourself in this position try warming the plug & / or the cylinder with a hot air gun.
The fuel : air mix burns at the same speed regardless of what it is in or how fast the engine is spinning.
So to burn completely before the exhaust port opens, high speed 2 stroke engines need a lot of advance .
With a timing chip, this is actually retard because at STP you can slow electricity down but you can't speed it up.
So with most 2 strokes the timing at starting is right on the verge of being too far advanced thus it becomes critical that it is exactly right.
On 4 strokes that are only spinning at 1/2 to 2/3 of a two stroke the timing is no where near as critical .
I understand what you're saying. The confusing part was that maybe what I thought I knew, was wrong. The coil can only get juice when the magnets pass the coil at a certain distance from the leg. And the coil, with a good key, is only going to allow the correct timing.
With a broken key, and carb cleaner, seems there would be some sort of hit, even with the timing 90 degree's off. If gas gets spark, regardless of where the piston is, there's gonna be an explosion. That's what I was trying to get.
And after taking the cover off again, looking at where the magnets were crossing the leg, and seeing the flywheel key still in tact, I did the same exact thing as I did for the first 200 pulls. Spray just a little carb cleaner into the carb, and pulled it about 4 times. Except this time, it fired off.
Why this time, and none of the other times? I can't say. I'm pretty embarrassed for making this thread now.
2 cycles hate me.
Liquid gasoline does not burn, gasoline vapor burns. If you put liquid fuel in the plug hole you run the risk of wetting the plug to the point that is arcs through the liquid fuel and no combustion.
Oh hell, i have worked on lots of demon possesed evil 2 strokes that hated me. Those things are a given. I have a voodoo priestess on retainer to cast out the demons. Only way to fix some of them. Sometimes you have to use FM on them.
New spark plugs have no glaze on the insulator nose inside the plug.
Modern fuels are conductive at cylinder pressure .
So the liquid or excessive spray condenses on the insulator providing a conductive path to ground so no spark inside the cylinder thus no bang.
Once this has formed you usually have top burn it off
The electrical resistance of air increases by the square of the pressure .
Those old Champion spark plug testers you sued to see in service stations who sold 3 times as many spark plugs than they should gave worked by increasing the pressure till eventually the spark stopped.
You spun the dial to show the customer that their spark plug was faulty at working pressure the sold them a new one .
It is the same principle as the moving gap magneto testers
In air a good mag will throw a spark from 1/4" to over 1" but inside the engine it will be lucky to jump a 0.050" plug gap .
Now because small 2 strokes start at higher compressions than mowers and run at faster speeds the coils are wound to produce optimum power at 7000 rpm or higher.
Thus the sparks at cranking speed is quite feeble
If they produced a big fat spark at cranking speeds the coil would burn out when running full speed
We sometimes think a 10,000 rpm 2 stroke engine will have a hard time sparking that fast but in reality it is a non issue. Cranking speed or 14000+ rpm the magneto puts out the same energy. Consider my 1966 396cid chevy with a standard 3 ohm coil and points. Turning at 6000 rpm the distributor is turning 3000 rpm and opening the points 8 times per rev. 3000 x 8 = 24000 spark pulses per minute. Above 6000 rpm you needed a magneto or a dual point distributor. The operating speeds of small engines from cranking speed to 15000 rpm is insignifigant to a magneto ignition. Some chainsaws have speed limited coils. At somewhere around 12000rpm the saw starts "blubbering" and folks think the coil can't keep up when in reality it is designed that way.BTW, do plugs throw a thicker spark at lower RPM's? Say like when one is being cranked?
Don't get trapped in the illusion. Thinking somewhat outside the illusion helps.
The service manual will provide you a hint of what may be bad....Get a copy of it or someone here that has it should read it and then post the info. Hint: It is in section 7. Bert's and Scrubcadet thinking is on track if this is the cause. Won't be the first time I have seen it.
Also technical bulletin 25.2005 needs to be referenced when comes to the flywheel. The IPL only references one flywheel and ignition coil setup but does note the TB.
Something I haven't needed but I should get it anyways.