r/stihl • u/robertking1991 • 1d ago

Coil help. Anyone?

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Hi all. Got a 460 that won’t start or give me a spark. I’m getting 1.8 across the plug and the earth circuit seems to be okay. Anyone know if this is enough? My 131 generates 1.6 and works fine. Starting to pull my hair out! Cheers

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2

u/PRAK11147 1d ago

Have you tried a new spark plug? Tried unplugging grounding wires to coil?

2

u/robertking1991 1d ago

Tried both, no luck 😬

1

u/PRAK11147 14h ago

Tried removing muffler to check piston for scoring?

Coil corroded?

2

u/iscashstillking 6h ago

This is an mTronic machine right?

1

u/robertking1991 4h ago

Yeh. Has made the diagnosing tricky with my limited knowledge

2

u/iscashstillking 4h ago

So this machine does not have an 'ignition module' proper, it has a control unit and that's why it costs $170.

There are also two revisions to said control unit; to get the right part number have your serial handy when you call the dealer.

As far as troubleshooting a no spark condition, the best you can do for right now is make sure the kill switch isn't actively killing things even when you don't want it to, i.e. make sure the switch and wiring are not shorted somewhere along the path. If that doesn't give you a clue then I would take it to the dealer and have them hook it up to the computer and see if the ignition module is alive or not.

1

u/robertking1991 55m ago

Ahhhh okay, brilliant. I’ll do that and see what we get. Many thanks!!

2

u/ReeferRivas 1d ago

I usually don't mess with measuring voltage. In my opinion, you either have reliable spark or not.

If you've changed the spark plug and still nothing then the issue is simply with the coil. When you pull the cord to start the engine it of course rotates a flywheel and on that flywheel is a magnet. When the magnet passes near the coil it produces a spark. Seems that's not happening here!

A new coil is cheaper than I expected the first time I ran into this, usually they're like $10-$50 for off-brand and then a genuine is probably 3x more expensive. I've never attempted to repair a faulty coil itself, always wondered if I could, usually there's some epoxy nonsense keeping everything in place and what I usually do is replace with a new off brand coil and am on my way!

Hope it helps!

1

u/robertking1991 1d ago

Thanks dude, going to take this advice! Many thanks!!

1

u/ReeferRivas 18h ago

Glad I could offer some insight! If a new coil doesn't produce spark - idk tbh... never had it happen! You'll have to update us with your findings haha

1

u/Tritiy428 1d ago

Well, I guess you should disassemble it at this point, check coil gap and if it's won't start, order a new one. Aftermarket coils works too...