I have an older snowblower I am trying to get running. I have no spark. I ran some fine sandpaper over the flywheel magnets and at the coil pickups. Still no spark. How do I test the coil and what else should I look for?

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'85 300SD (formerly california emissions)
'08 Chevy Tahoe
'93 Ducati 900 SS
'79 Kawasaki KZ 650
'86 Kawasaki KX 250
'88 Kawasaki KDX200
'71 Hodaka Ace 100
'72 Triumph T100R

Check the coils with an ohmmeter. Does it have points?

I am stuck at work right now so I did up a quick paint sketch of what I did. The round thing is the flywheel that has what look like magnets around the sides. The gaps where the arrows are pointing I cleaned with some 400 grit sandpaper.

Attached Thumbnails

 

__________________
'85 300SD (formerly california emissions)
'08 Chevy Tahoe
'93 Ducati 900 SS
'79 Kawasaki KZ 650
'86 Kawasaki KX 250
'88 Kawasaki KDX200
'71 Hodaka Ace 100
'72 Triumph T100R

Rust on the flywheel, while unsightly, rarely affects performance.
Pull the flywheel, under it there might be a cover, with the ignition points under it. Or, it may have a solid state setup.
At least with points, you can diagnose and repair. With SS, you simply replace the module.

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1982 300SD " Wotan" ..On the road as of Jan 8, 2007 with Historic Tags

It would still have points with this setup? I thought the magnets passing the coil produced a current which then fired the plug.

It is a pretty old snowblower, probably from early 70's.

__________________
'85 300SD (formerly california emissions)
'08 Chevy Tahoe
'93 Ducati 900 SS
'79 Kawasaki KZ 650
'86 Kawasaki KX 250
'88 Kawasaki KDX200
'71 Hodaka Ace 100
'72 Triumph T100R

If it's that old, it has or had points. They are probably behind the flywheel.

The magnet passing the coil induces a current, yes, but it is the breakdown of the current caused by the points opening that creates the high voltage in the secondary circuit.

Modern magnetos don't use points, but rather an electronic interrupter circuit that is timed based on the magnet's position.

Thats a magneto, no points or electronics.

I'm no expert at them, but I can work it.
As the magnet passes the coil a spark is generated.

There is probably a wire attached to the coil, if grounded (maybe NOT grounded) it will not fire, this is the key shut off.

Beyond that I don't think there is any way to test except to replace and if it works now.

__________________
KLK, MCSE

1990 500SL

I was always taught to respect my elders.
I don't have to respect too many people anymore.

I am not aware of a magneto which lacks points or electronics.

The B&S engine on my lawn tractor.

The coil connects directly to the spark plug.

__________________
KLK, MCSE

1990 500SL

I was always taught to respect my elders.
I don't have to respect too many people anymore.

It either has a transistorized circuit inside the module, or a point set under the flywheel, depending on when it was made.

Replacement magnetos are all electronic, so you remove or disconnect the points if you replace the magneto in your unit. But if you have points, you are pretty unlikely to ever need to replace the magneto.

This from wiki:
* Magnetron Electronic Ignition - This solid state ignition system, introduced by B&S in 1981, eliminated the ages-old points and condenser setup that had plagued many customers who had used a gasoline engine for years. This setup is also available in retrofit kits, but these are only compatible with B&S's external ignition engines produced since January, 1963. However, its rival Tecumseh had made a capacitor discharge ignition setup since 1968, for their cast iron engine models, expanding it to vertical shaft engines powering lawn mowers in late 1976 before the setup came full circle in August, 1984 for all of their engine lines. The Magnetron was actually born out of the Magnavac system, introduced by B&S in 1976.[12]


Yes, indeed, there is more to it than the flywheel magnet and coil.

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1982 300SD " Wotan" ..On the road as of Jan 8, 2007 with Historic Tags

Sorry neither.

I have replaced the magneto twice, and rebuilt the engine tearing it down to almost nothing.
It's a Simplicity from the early 90s, actually early/mid 80s desgin.

__________________
KLK, MCSE

1990 500SL

I was always taught to respect my elders.
I don't have to respect too many people anymore.

Well, I'll have to believe you if you said that you broke open the coil module and found no sign of electronics. It baffles me as to how it could work, but ok.

I did say I was no expert, but I can work on them.

So we'll let some more knowledgable folks step in and give us the details.
I have an idea, but it is really just an educated guess.

__________________
KLK, MCSE

1990 500SL

I was always taught to respect my elders.
I don't have to respect too many people anymore.

Engine model, code, or serial #'s would be helpful.