Engine Trouble Two-Stroke Motor Suddenly No Idle

[Nickt919]

Look at post #16 in this thread.

That said.. if the engine was running fine AND the magneto nut is still tight, then it is unlikely the key allowed the magnet to move.

It’s not impossible but not probable.

You can verify the magnet is in the correct position by taking the magnet rotor nut off and sliding the the magnet off the shaft.

IF..the key is still in the crankshaft slot AND it is not damaged put the magnet back on, washer back on, nut back on and tighten it.

If the magnet is removed with the magneto still installed, the magnet will try to stick to the magneto lamenated bars. It takes a bit of deliberate force to push it back on and not have the key get pushed out the slot.

It’s easier to remove the magneto before removing the rotor magnet but you will have to reset the spacing with thin cardboard or old credit card to get the spacing correct and equal on top and bottom.

Pay close attention of how the magnet comes off. It has to go back in the same way…provided it was was on correctly to start with.

To verify this correct installation…

Put the piston at top dead center..TDC.. all the way up.
When the piston is at TDC the key slot on the crank should be at about the 1 o’clock position. When the magnet is now installed the magnet slot at 1 o’clock and the widest parts of the rotor magnet straight across from each other and horizontal.

 

[Bary Kiddo]

You have to unscrew it and see if it has shifted off the woodruff key its on because without taking the nut off you cant visibly tell if it has shifted or not due to the nut covering the woodruff key.

I thought the woodruff key is designed to stay stationary and hold the rotor in place: Actually, I already checked it and posted a photo earlier - it's undamaged and hasn't shifted, so it's fine.

 

[Nickt919]

I had suggested a carb issue earlier.

I still suspect this is it. Cleaning the carb may get you going again.

If all the things mentioned up to this point are actually correct and working then fuel delivery has to be the issue.


Dirt has a way of finding itself in even with a good fuel filter.

 

[Andrew1234]

I thought the woodruff key is designed to stay stationary and hold the rotor in place: Actually, I already checked it and posted a photo earlier - it's undamaged and hasn't shifted, so it's fine.

Then it might be the cdi and magneto id recommend getting a set on amazon for both the cdi and magneto on amazon for about 15 bucks

 

[Nickt919]

Change em both for peace of mind and save the old ones.

Once the engine is running correctly you can switch out one at a time and prove if it’s bad or not this way

If bad>>>pitch it
If good>>>save it

 

[Wyvern]

@Bary Kiddo
s**tz and grins, you try bypassing the kill switch? Would be a shame if all you needed was a $3 switch.

 

[robe]

@Bary Kiddo
s**tz and grins, you try bypassing the kill switch? Would be a shame if all you needed was a $3 switch.

The ohm test you suggested earlier showed the magneto windings were shorted. May just be dead and that's all there is to it. You can't tell by looking at it, try another.

 

[Wyvern]

The ohm test you suggested earlier showed the magneto windings were shorted. May just be dead and that's all there is to it. You can't tell by looking at it, try another.

I skimmed through and thought he replaced it and it still didn't work.

Ohm meter doesn't lie, it's definitely bad.

 

[Bary Kiddo]

Where can I get an ignition coil compatible with my bike model?

 

[Nickt919]

Because of the uncertainty of pin pointing this problem I’d think taking Andrew’s suggestion and get both cdi and magneto… $14 for both items..would be the thing to do.

Save the old ones. Once you get the engine running, you can switch out the cdi and magneto one at a time and prove whether one or both are bad. Throw out the bad component(s) and save the good one(s) for spares.

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